Chapter 4 The Central Islamic Lands | class 11th | ncert quick revision notes history

Class 11 History Notes Chapter 4 The Central Islamic Lands

  • Prior to the rise of Islam, Arabia was quite backward socially, politically, economically and religiously in the 7th century.
  • Before the rise of Islam, Arabia was dominated by the Bedouins, a nomadic tribe.
  • Family was the basic unit of the Arabian society. Patriarchal family system was prevalent in which the head of the family was the eldest male member.
  • The position of the women in the society was very deplorable.
  • Date-palm and milk were the main constituents of their food items.
  • Institution of slavery was also prevalent in the society. The slaves were treated ruthlesslyand were severely punished if broke the social norms. k
  • Prior to the rise of Islam, the trade was not much developed. It was because Bedouins Iwere always indulged in loot and plunder and trade routes were not safe.
  • The principle of‘Might is right’ prevailed in the society prior to the rise of Islam, because there was lack of a central authority.
  • Prophet Muhammad is regarded as one of the greatest personalities in the world history. He was born at Mecca in 570.
  • Reciting Raima, Namaz, Rauja, Zakat and Hajj are five pillars of Islam.
  • Islam laid special stress on the principle of equality and believed that all men are the descendants of Allah.
  • Islam strongly opposed idol worship.
  • The successors of Prophet Muhammad were called Khalifas (Caliphs).
  • The main duties of the Khalifas were to safeguard and spread Islam.
  • The Umayyad dynasty was founded by Muawiya in 661. The rule of this dynasty continued till 750.
  • The Abbasids came to power in 750. The foundation of Abbasids dynasty was laid down by Abu-ol-Abbas in 750.
  • 9th century witnessed the downfall of the Abbasid empire. Taking the advantage of this, several sultanates emerged.
  • The economic condition of Islamic world, during the medieval period was very prosperous.
  • During medieval period, a new sect arose among the people having faith in Islamic doctrines, known as sufi sect.
  • The Sufis were liberal in their thought and they dedicated their lives for the service of humanity and propagation of Islam.
  • Ibn Sina was a great philosopher and a medical practitioner from Arabia. He was also known as Avicenna in Europe.

Important terms:

  • Bedouins: The nomadic tribe of Arabia.
  • Umma: The society founded by Prophet Muhammad.
  • Hizrat: The event of Prophet Muhammad’s emigration from Mecca to Medina.
  • Zakat: A religious tax collected from Muslims.
  • Jaziya: A tax imposed upon the non-Muslims.
  • Dhimmis: They were the protected people who paid tax to the government for the protection of their life and property.
  • Synagogues: Places of worship for the Jews.
Timeline
595Muhammad marries Khadija, a wealthy Meccan trader who later supports Islam
610-12Muhammad has first revelation; first public preaching of Islam (612)
621First agreement at Aqaba with Medinan converts
622Migration from Mecca to Medina. Arab tribes of Medina (ansar) shelter Meccan migrants (muhajir)
632-61Early caliphate; conquests of Syria, Iraq, Iran and Egypt; civil wars
661-750Umayyad rule; Damascus becomes the capital
750-945Abbasid rule; Baghdad becomes the capital
945Buyids capture Baghdad; literary and cultural efflorescence
1063-1092Rule of Nizamul mulk, the powerful Saljuq wazir who established a string of madrasas called Nizamiyya; killed by Hashishayn (Assassins)
1095-1291Crusades; contacts between Muslims and Christians
1111Death of Ghazali, the influential Iranian scholar who opposed rationalism
1258Mongols capture Baghdad
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Chapter 3 An Empire Across Three Continents | class 11th | ncert quick revision notes history

Class 11 History Revision Notes for An Empire Across Three Continents of Chapter 3


SNIPPETS FROM THE CHAPTER

Sources: There is a rich collection of sources to study Roman history, like – texts, documents and material remains. 
1. Archaeological : a) Amphitheater, b) Amphorae, c) Colosseum, d) Statues, e) Aqueducts
2. (Literary) Written : (A) Texts –  Histories written by Contemporary Historians (B) Documents
3. Aerial Photographs

Documentary sources include mainly inscriptions and papyri. Inscriptions were usually cuton stone, so a large number survive, in both Greek and Latin.

The ‘papyrus’ was a reed-like plant that grew along the banks of the Nile in Egypt and was processed to produce a writing material that was very widely used in everyday life.

Thousands of contracts, accounts, letters and official documents survive ‘on papyrus’ and have been published by scholars who are called ‘papyrologists.

Boundaries of Roman Empire

  • The ancient Roman empire which was spread across the three continents namely – Europe, Asia and Africa.
  • To the North, the boundaries of the empire were formed by two great rivers – the Rhine and the Danube.
  • To the South, by the huge expanse of desert called the Sahara.
  • To the East river Euphrates and to the West Atlantic Ocean.
  • This vast stretch of territory was the Roman Empire. That is why Roman Empire is called an Empire across Three Continents.
  • The Mediterranean Sea is called the heart of Rome’s empire.

Division of Roman Empire: 

  • The Roman Empire can broadly be divided into two phases, ‘early’ and‘late’, divided by the third century as a sort of historical watershed between them.
  • In other words, the whole period from the beginning of Roman Empire to the main part of the third century can be called the ‘early empire’, and the period from the third century to the end called the ‘late empire’ or ‘late antiquity’.

THE EARLY EMPIRE

Administration: i. The Army – ii. The Senate – iii. the Aristocracy – iv. The Emperor – v. Republic – vi. Provincial Territory – vii. Taxation

  • Many languages were spoken in the empire, but for the officially Latin and Greek were the most widely used.
  • The regime established by Augustus, the first emperor, in 27 BCE was called the ‘Principate’ (which means he was ‘leading citizen’, ‘Princeps‘ in Latin, not the absolute ruler). He ruled till 14 BCE and brought to an end the chaotic condition prevailing in Roman empire.
  • The Principate was advised by the Senate, which had existed in Rome for centuries. This body which had controlled Rome earlier, in the days when it was a Republic, and remained a body representing the aristocracy, that is, the wealthiest families of Roman and, later, Italian descent, mainly landowners.
  • Next to the emperor and the Senate, the other key institution of imperial rule was the army. Rome had professional conscripted army, which was forcibly recruited. Military service was compulsory for certain groups or categories of the population for a minimum of 25 years.
  • The emperor, the aristocracy and the army were the three main ‘players’ in the political history of the empire. The success of individual emperors depended on their control of the army, and when the armies were divided, the result usually was civil war. Except for one notorious year (69 CE), when four emperors mounted the throne in quick succession.

Emperors:  a) Nero, b) Julius Caesar, c) Octavian Augustus, d) Tiberius, e) Trajan

  • Roman empire made unprecedented growth in the field of literature during Augustan age. Augustus played a significant role in expansion of Roman empire.
  • The ‘Augustan age’ is remembered for the peace it ushered in after decades of internal strife and centuries of military conquest.
  • Augustus appointed Tiberius, his adopted son, as his successor who ruled from 14-37 CE. The empire he was already so vast that further expansion was felt to be unnecessary.
  • Trajan was a famous Roman emperor who ruled from 98-117 CE. He made an immense contribution in expanding Roman empire. The only major campaign of expansion in the early empire was Trajan’s fruitless occupation of territory across the Euphrates, in the years 113-17 CE abandoned by his successors.

Territories: The Roman Empire had two types of territories – dependent kingdoms and provincial territory. The Near East was full of dependent kingdoms but they disappeared and were swallowed up by Rome. These kingdoms were exceedingly wealthy, for example Herod’s kingdom yielded 5.4million denarii per year, equal to over 125,000 kg of gold per year.
A city in the Roman Empire was an urban centre with its own magistrates, city council and a ‘territory’ containing villages which were under its jurisdiction. Thus, one city could not be in the territory of another city, but villages almost always were included.

THE THIRD CENTURY CRISIS:  The first two centuries were free fromcivil war,therefore, it was known as period of peace, prosperity and economic expansion. External warfare was also much less common in the first two centuries. But the third century brought in the first sign of internal conflict.

  • From the 230s, the Roman Empire found itself fighting on several fronts simultaneously. An aggressive dynasty called the ‘Sasanians’,  emerged in 225 which expanded rapidly just within 15 years in the direction of the Euphrates. Shapur I, the Iranian ruler, claimed he had crushed Roman army of 60,000 and even captured the eastern capital of Antioch.
  •  Simultaneously, a whole series of Germanic tribes or rather tribal confederacies began to move against the Rhine and Danube frontiers, and the  entire period from 233 to 280 saw repeated invasions of a whole lone of provinces that stretched from the Black Sea to the Alps and Southern Germany. The Romans were forced to abandon much of the territory beyond the Danube.
  • There was a rapid succession of emperors in this century (25 emperors in 47 years!) is an obvious symptom of the strains faced by the empire in this period.

Gender, Literacy, Culture

  • The system of nuclear family in the Roman society was one of its modern feature. The family used to be patriarchal in nature. Slaves were included in the family.
  •  Marriages were generally arranged, and there is no doubt that women were often subject to domination by their husbands.
  • The literacy rate was casual and varied greatly between different parts of the empire.
  • The cultural diversity of the empire was reflected in many ways. Numerous languages that were spoken in Roman Empire were – Aramaic, Coptic,Punic, Berber and Celtic. But many of these linguistic cultures were purely oral, at least until a script was invented for them.  Among the above mentioned languages Armenian began to be written as late as the fifth century.

A. Sources of Entertainment

  • Colosseum – Huge place where gladiators fought with beast. It could accommodate 60,000 people.
  • Amphitheatre – It was used for military drill and for staging entertainments for the soldiers.
  • Urban populations also enjoyed a much higher level of entertainment, for example, one calendar tells us that spectacula (shows) filled no less than 176 days of the year!


B. CRAFT & INDUSTRY

  • Minting
  • Mining
  • Amphorae
  • Making Papyrus scrolls
  • Public baths were a striking feature of Roman urban life

Economic expansion

  •  The empire had a substantial economic infrastructure of harbours, mines, quarries, brickyards, olive oil factories, etc. Wheat, wine and olive-oil were traded and consumed in huge quantities, and they came mainly from Spain, the Gallic provinces, North Africa, Egypt and, to a lesser extent, Italy, where conditions were best for these crops.
  • Liquids like wine and olive oil were transported in containers called ‘amphorae’.Spanish producers succeeded in capturing markets for olive oil from their Italian counterparts. This would only have happened if Spanish producers supplied better quality oil at lower prices.
  • The Spanish olive oil of this period was mainly carried in a container called ‘Dressel 20’.
  • The empire included many regions that had a reputation for exceptional fertility. Italy, Sicily, Egypt and southern Spain were all among the most densely settled or wealthiest parts of the empire. The best kinds of wine, wheat and olive oil came mainly from numerous estates of these territories.
  • Diversified applications of waterpower around the Mediterranean as well as advances in water-powered milling technology, the use of hydraulic mining techniques in the Spanish gold and silver mines and the gigantic industrial scale on which those mines were worked.
  • The existence of well-organized commercial and banking networks and the widespread use of money are all indications of Roman economy.
  • A strong tradition of Roman law had emerged by the fourth century, and this acted as a brake on even the most fearsome emperors.

WORKERS:

  • Slavery was an institution deeply rooted in the ancient world, both in the Mediterranean and in the Near East, and and not even Christianity when it emerged and triumphed as the state religion (in the fourth century) seriously challenged this institution. Under Augustus there were still 3 million slaves in a total Italian population of 7.5 million.
  • With establishment of peace in the first century, the supply of slaves tended to decline and the users of slave labour had to turn either to slave breeding or to cheaper substitutes.
  • The Roman agricultural writers paid a great deal of attention to the management of labour. Columella, a first-century writer who came from the south of Spain, recommended that landowners should keep a reserve stock of implements and tools, twice as many as they needed, so that production could be continuous, ‘for the loss in slave labour time exceeds the cost of such items’.
  • The position of slave in Roman Empire was miserable as they were forced to work on the estate for 10 to 18 hours.

SOCIAL DIVISION
(A) Presbyterian
(i) The Aristocratic class
(ii) Second Class

(B) Plebeian
(i) The lower Class
(ii) Slaves

  • The social structures of the empire as follows: Senators, Equites (horse men and knights), the respectable section of the people (middle class), lower class and finally the slaves.
  • In the early third century when the Senate numbered roughly 1,000, approximately half of all senators still came from Italian families. By the late empire,the senators and the Equites had merged into a unified and expanded aristocracy.
  • The ‘middle’ class now consisted of the considerable mass of persons connected with imperial service in the bureaucracy. Below them were the vast mass of the lower classes known collectively ashumiliores (literally- ‘Lower’).They comprised a rural labour force.
  • The late Roman bureaucracy, both the higher and middle echelons, was a comparatively affluent group because it drew the bulk of its salary in gold and invested much of this in buying up assets like land.  There was a great deal of corruption, especially in the judicial system and in the administration of military supplies.

JEWISH WAR 

  • Roman people were polytheists and used to worship several gods and goddesses. Their popular deities were Jupiter, Mars, Juno, Minerva and Isis.
  • One of the most important religious sects practiced in the Roman Empire from about the first to the fourth century was Mithraism.
  • The other great religious tradition in the empire was Judaism. It considered Jehova as the creator of the universe.
  • But Judaism was not a monolith either, and there was a great deal of diversity within the Jewish communities of late antiquity. Thus, the ‘Christianisation’ of the empire in the fourth and fifth centuries was a gradual and complex process.
  • Polytheism did not disappear overnight, especially in the western provinces, where the Christian bishops waged a running battle against beliefs and practices they condemned more than the Christian laity (the ordinary members of a religious community as opposed to the priests or clergy who have official positions within the community) did.
  • The boundaries between religious communities were much more fluid in the fourth century than they would become thanks to the repeated efforts of religious leaders, the powerful bishops who now led the Church, to rein in their followers and enforce a more rigid set of beliefs and practices.


LATE ANTIQUITY 
‘Late antiquity’ is the term now used to describe the final, fascinating period in the evolution and break-up of the Roman Empire and refers broadly to the fourth to seventh centuries. The fourth century itself was one of considerable ferment, both cultural and economic.

Cultural features of the Roman world from the Fourth to Seventh Centuries: 

Emperors and their Achievements
I. Constantine’s Achievements

a. Overexpansion of the Empire: 
b. Capital at Constantinople:  The other area of innovation was division of Roman Empire into east and west and the creation of a second capital at Constantinople (at the site of modern Istanbul in Turkey, and previously called Byzantium), surrounded on three sides by the sea.
c. Christianity was made official religion:  At the cultural level, the period saw momentous developments in religious life, with the emperor Constantine deciding to make Christianity the official religion, and with the rise of Islam in the seventh century.
d. Monetary sphere: Constantine founded the new monetary system on gold and there were vast amounts of this in circulation. Constantine’s chief innovations were in the monetary sphere, where he introduced a new denomination, the solidus, a coin of 4½ gm of pure gold that would in fact outlast the Roman Empire itself. Solidi were minted on a very large scale and their circulation ran into millions.
II. Diocletian’s Achievements
a. Abandons territories of little economic and strategic importance: Overexpansion had led Diocletian to ‘cut back’ by abandoning territories with little strategic or economic value.
b. Duces: Diocletian also fortified the frontiers, reorganised provincial boundaries, and separated civilian from military functions, granting greater autonomy to the military commanders (duces), who now became a more powerful group.
III. Justinian’s Achievements: 
a. Justinian Code
b. Expansion of Empire: The reign of Justinian is the highwater mark of prosperity and imperial ambition. Justinian recaptured Africa from the Vandals (in 533) but his recovery of Italy (from the Ostrogoths) left that country devastated and paved the way for the Lombard invasion.
c. Monetary Sphere:  Monetary stability and an expanding population stimulated economic growth. Egypt contributed taxes of over 2½ million solidi a year (roughly 35,000 lbs of gold) in the reign of Justinian in the sixth century.
i. Glass factories established
ii. Introduction of Solidus
iii. Urban Prosperity
DOWNFALL OF THE EMPIRE

  • The general prosperity was especially marked in the East where population was still expanding till the sixth century, despite the impact of the plague which affected the Mediterranean in the 540s.
  • In the West, by contrast, the empire fragmented politically as Germanic groups from the North (Goths, Vandals, Lombards, etc.) took over all the major provinces and established kingdoms that are best described as ‘post-Roman’
  • The Visigoths in Spain was destroyed by the Arabs between 711 and 720, that of the Franks in Gaul (c.511-687) and that of the Lombards in Italy (568-774). These kingdoms foreshadowed the beginnings of a different kind of world that is usually called ‘medieval
  • By the early seventh century, the war between Eastern Rome and Iran had flared up again, and the Sasanians who had ruled Iran since the third century launched a wholesale invasion of all the major eastern provinces (including Egypt).
  • Roman and Sasanian empires had fallen to the Arabs in a series of stunning confrontations.
  • Those conquests, extended up to Spain, Sind and Central Asia, began, in fact, with the subjection of the Arab tribes by the emerging Islam state.

Timeline: Refer to Page No. 75 of the chapter/ Theme  of the Text book
Key Words: Civil War, Republic, Senate,  Dressel 20/ Amphorae, Draconian
Transhumance: Herdsman’s regular annual movement between higher mountain regions and low lying ground in search of Pasture..

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Chapter 2 Writing and City Life | class 11th | ncert quick revision notes history

Class 11 History Revision Notes for Writing and City Life of Chapter 2


SNIPPETS FROM THE CHAPTER
I. Ancient Mesopotamia 
Geography: 

  • City life began in Mesopotamia (Mesopotamia is derived from the Greek words ‘mesos’, meaning middle, and ‘potamos’, meaning river.)
  • It is a flat land between the Euphrates and the Tigris rivers that is now part of the Republic of Iraq.
  • In the north, there is a stretch of upland called a steppe, where animal herding offers people a better livelihood than agriculture
  • Agriculture began between 7000 and 6000 BCE.
  • Soil was very fertile here but agriculture was threatened because of natural causes.
  • Ur, Lagash, Kish, Uruk and Mari were some of its important cities.
  • The excavation work started 150 years ago.

Urbanisation

  • Mesopotamian civilization was based on definite plan. 
  • Cities and towns are develop when an economy develops in spheres other than food production that it becomes an advantage for people to cluster in towns.
  • Urban economies comprise besides food production, trade, manufactures and services.
  •  There is social organisation in place
  • Helpful for the city manufacturers.
  • The division of labour is a mark of urban life.

Movement of Goods into cities

II. Mesopotamian & Writing  Modern Writing
1. Mesopotamian Writing:

  • The first Mesopotamian tablets, written around 3200 BCE, contained picture-like signs and numbers.
  • Writing began when society needed to keep records of transactions – because in city life transactions occurred at different times, and involved many people and a variety of goods
  • Mesopotamians wrote on tablets of clay.

2. Modern Writing: The greatest legacy of Mesopotamia to the world is its scholarly tradition of time reckoning and mathematics, calender.
III. Political Factors

  • From about 1100 BCE, when the Assyrians established their kingdom in the north, the region became known as Assyria. The first known language of the land was Sumerian.
  • Writing was used not only for keeping records, but also for making dictionaries, giving legal validity to land transfers, narrating the deeds of kings, and announcing the changes a king had made in the customary laws of the land.
  • It can be inferred that in Mesopotamian understanding it was kingship that organised trade and writing.

Religious Factors

  • Early settlers (their origins are unknown) began to build and rebuild temples at selected spots in their villages. The earliest known temple was a small shrine made of unbaked bricks. Temples were the residences of various gods.
  • Temples were centres of religious activities. They were dedicated to different gods and goddess.

(5000 BCE – Settlements began to develop in southern Mesopotamia)

IV. Social Factors
1. Life in the City – Mesopotamian society the nuclear family was the norm, although a married son and his family often resided with his parents. The father was the head of the family.

  • A ruling elite had emerged
  • Had a major share of wealth
  • Followed nuclear family system and  patriarchal system
  • Condition of women
  • System of marriages

2. Ur  – was a town, one of the earliest cities. It is often compared with Mohenjodaro
3.In Mesopotamian tradition, Uruk was the city par excellence, often known simply as The City.
V. Economic Factors

  1. Urbanism
  2. Trade
  3. Record of transaction
  • Writing began in Mesopotamia in 3200 BCE.
  • Writing became as a records of transactions
  • 2600 BCE the letters became cuneiform and language was Sumerian

VI. Cultural Factors
1. System of Writing:

  • Writing was skilled craft
  • It conveyed in visual form of system of sounds of a particular language

2. Literacy:

  • Writing reflected the mode of speaking
  • King and very few could read
  • Official letter from a king could be read

3. Uses of Writing:

  • Connections between city life trade and writing is brought out.
  • It has brought out in a long Sumerian epic poem about Enmerkar (king)
  • Kingship was able to organise trade and writing

4. Inter Mixture culture:

  • Mesopotamian society and culture were open to different people and cultures.
  • Thus the vitality of the civilisation was of course – an intermixture culture

Cuneiform Script
1. Meaning: It is a script of Mesopotamia. The word ‘Cuneiform’ is derived from the Latin words cuneus, meaning ‘wedge’ and forma, meaning ‘shape’. Cuneiform letters were wedge shaped, hence, like nails.
2. Uses: By 2600 BCE or so, the letters became cuneiform, and the language was Sumerian. Cuneiform writing in the Akkadian language continued in use until the first century CE, that is, for more than 2,000 years.
VII. Sources
i. Tables (Written around 32000 BCE)
ii. Bible (Old Testament)
iii. British Museum
iv. Texts
VIII. Greatest Legacy of Writing
1. Scholarly tradition of time reckoning
A. Calendar

  • Division of years
  • Division of Months
  • Division of Weeks
  • Division of Days
  • Division of Hours
  • Division of Minutes
  • Division of Seconds

B. Recorder of Modern world Phenomenon past
C. Literature: Gilgamesh, which was written on twelve tablets, was the famous epic of Mesopotamia.  It was the work of Uruk who was the ruler of Mesopotamia in 2700 BCE.
2. Mathematical contribution

  • Tables with multiplication and division
  • Square
  • Square route tables
  • Tables of compound interest
  • Problem regarding
  • A field of area
  • Volume of water

IX. Timeline – refer to the text book Page No.48
X. Key Words : Mesopotamia, Cuneiform, Syllable, Steles, Nuclear Family.

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Chapter 1 From the Beginning of Time | class 11th | ncert quick revision notes history

From the Beginning of Time

❇️ Human :-

🔹 56 lakh years ago such creatures appeared on the earth which we can call humans. Modern humans arose 160,000 years ago.

❇️ Two theories of the emergence of modern man :-

🔹Regional Continuity Model Theory: – Humans originated at different places in many regions.

🔹 Theory of Substitution :- Humans originated in Africa and spread from there to different areas.

❇️ Archaeologist :-

🔹It is the scientist who studies human history through the study of excavated remains.

❇️ The main sources of information about the history of primitive man :-

🔹 Fossils.

🔹 Stone tools.

🔹 There are paintings done by humans in caves.

❇️ Genus :-

🔹 For this the word ‘Vansh’ is used in Hindi.

❇️ Fossils :-

🔹 ‘Fossil’ is used to refer to the remains or impressions of an old plant, animal or human that have been transformed into a stone, often embedded in a rock and then lying in that form for millions of years.

❇️ Species :-

🔹 Species is a group of organisms whose male and female can produce children together and their children are also capable of further reproduction i.e. to produce offspring.

❇️ On the Origin of Species :-

🔹The book On the Origin of Species, written by Charles Darwin, was published on 24 November 1859, in which it was argued that humans evolved from animals. It has evolved gradually from animals and has come to its present form.

❇️ Primate :-

🔹 Mammals are a much larger group of animals. This includes apes, langurs and humans.

❇️ Homo :-

🔹 Is a Latin word which means “man”. It includes both men and women.

️ ❇️ Types of Homo :-

🔸Homo – Scientists have divided it into many species. 

🔹 Homo Hawillis: – equipment manufacturer.

🔹 Homo erectus – directly stand to walk on his feet.

🔹 Homo sapiens – Citnshil man.

❇️ Australopithecus :-

🔹 It is derived from the Latin word ‘Austral’ meaning southern and Greek ‘Pithikus’ meaning ‘monkey’. This name was given because in the middle form of man, many features of his ape state remained intact.

❇️ Features of Australopithecus :-

🔹 The brain of Australopithecus was larger than that of Homo.

🔹 Their jaws were heavy.

🔹 Their teeth were also big.

🔹 The efficiency of the hands was limited.

🔹 The ability to walk standing upright was not high.

🔹 He used to spend most of his time on the trees.

❇️ Difference between Australopithecus and Homo :-

🔸Australopithecus :-

🔹 The brain of Australopithecus was larger than that of Homo.

🔹 Their jaws were heavy.

🔹 Their teeth were also big.

🔹 The efficiency of the hands was limited.

🔹 The ability to walk standing upright was not high.

🔹 He used to spend most of his time on the trees.

🔸Homo :-

🔹 Their brain was smaller than that of Australopithecus.

🔹 His jaws were light.

🔹 Their teeth were of small size.

🔹 They used to make good use of hands.

🔹 They had more ability to walk standing upright.

❇️ Hominoid :-

🔹 They are different from monkeys in many ways, their body is bigger than monkeys and they do not have tail.

❇️ Features of Hominoid :-

🔹 Hominoids differ from monkeys in many ways.

🔹 Their body is bigger than that of monkeys and they do not have a tail.

🔹 The period of evolution and dependence of hominids would have been much longer.

❇️ Hominid :-

🔹’Hominid’ are members of the family called Hominidae, this family includes all forms of human beings. 

❇️ Characteristics of Hominid :-

🔹 The size of his brain was big.

🔹 They had the ability to stand straight on their feet.

🔹 He used to walk on two legs.

🔹 Special ability in his hands by which he could make tools and use them.

❇️ Evidence of the emergence of hominids in Africa :-

🔸There are two proofs for this:

🔹 The group of African apes (apes) is closely related to hominids.

🔹The oldest hominid fossils, from the genus Australopithecus, have been found in East Africa. And the fossils found outside Africa are not that old.

❇️ Difference between Hominid and Homo Nide :-

🔸Hominid :-

🔹 Their brain was smaller than that of Homonido.

🔹 He used to stand straight and walk on the last two legs. 

🔹 Their hands were of a special kind, with the help of which they could make weapons and use them.

🔹 Their origin is believed to be about 56 lakh years ago.

🔸Hominidae :-

🔹 Their brain is larger than that of hominids.

🔹 They were quadrupeds, that is, they walked on all four legs, but the front part of their body and both the front legs were flexible.

🔹 They had a different hand build and they did not learn to use tools.

🔹 Their origin is believed to be before the origin of hominids.

❇️ How did the primitive man take food?

🔹 Primitive humans used to consume food in different ways. 

🔹 Storage    

🔹 Hunting      

🔹 Fishing      

🔹 Erasure

❇️ Eradication :-

🔹 It means cleaning or eating discarded things.

❇️ Communication, Language and Art :-

🔹 There are many types of views on the development of language such as :-

🔹 Hominid language included gestures (gestures) or hand movements (shakes).

🔹 Before spoken language, oral or (a)-verbal communication such as singing or humming was used.

🔹 Man’s speech probably started with the action of invocations or calls, as is seen in male and apes. In the early stages, humans would use very few sounds in speaking. Gradually these sounds developed into language later on.

❇️ Origin of spoken language :-

🔹 It is believed that Homo habilis had some characteristics in the brain that would have made it possible for him to speak. Language first evolved 20 million years ago. The development of vocal system took place about two lakh years ago. It is especially related to modern man.

❇️ Hunter Collectors Society :-

🔹 These societies were engaged in hunting as well as economic activities, such as exchanging and trading small things found in the forests.

❇️ Hadza crowd :-

🔹 It is a small group of hunters and gatherers, who live around the lake formed in the rift valley of “Lake Iasi” salt water. These people hunt all kinds of animals except elephants and eat their meat.

🔹 The Hadza people do not assert their rights over the land and its resources. Despite having unlimited amount of animals available for hunting, these people mainly depend on wild greens and vegetables for their food. Probably 80% of their food is vegetable.

❇️ Features of Altamira Cave :-

🔹 Altamira is a cave-site located in Spain. This cave is famous for its ceiling paintings. Some kind of paste has been used instead of color in its paintings. These paintings are very old, but they look modern in appearance, which even archaeologists are unable to believe.

❇️ Beginning of Ice Age :-

🔹 The ice age started about 2.5 million years ago, with the polar glaciation. In this, large parts of the earth were covered with ice, due to which there were big changes in the condition of climate and vegetation. Due to the decrease in temperature and rainfall, forests were reduced and the area of ​​grasslands increased.

❇️ End of Ice Age :-

🔹 The last ice age ended about thirteen thousand years ago. Due to which many changes came in humans.

🔹 For example, farming, animal husbandry etc

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Chapter 8 Index Number | class 11th | ncert quick revision notes Statistics for Economics

Statistics for Economics Class 11 Notes Chapter 8 Index Numbers

Index Number
An index number is a statistical device for measuring changes in the magnitude of a group of related variables. It represents the general trend of diverging ratios from which it is calculated.
According to Croxton and Cowden, “Index numbers are devices for measuring difference in the magnitude of a group of related variables.”

Methods of Constructing Index Numbers
Statistics for Economics Class 11 Notes Chapter 8 Index Numbers 1

Construction of Simple Index Numbers
There are two methods of constructing simple index numbers.
(i) Simple Aggregative Method In this method, we use the following formula
P01=ΣP1ΣP0×100
Here, P01 = Price index of current year
ΣP1 = Sum of prices of the commodities in the current year
ΣP0 = Sum of prices of the commodities in the base year
(ii) Simple Average of Price Relatives Method
According to this method, we first find out price relatives from each commodity and then take simple average of all the prices relatives.
Price relatives, P01 =  Current year price (P1) Base year price (P0)×100
We can find out price index number of the current year by using the following formula
P01=∑[P1P0×100]N

Construction of Weighted Index Numbers
(i) Weighted Average of Price Relative Method
According to this method, weighted sum of the price relatives is divided by the sum total of the weight. In this method, goods are given weight according to their quantity, thus
P01=ΣRWΣW
Here, P01 = Index number for the current year in relation to the base year
W = weight
R = price relative
(ii) Weighted Aggregative Method Under this method, different goods are accorded weight according to the quantity bought therefore, suggested different techniques of weighting some of well known methods are as under
Statistics for Economics Class 11 Notes Chapter 8 Index Numbers 2
Fisher’s Method is considered as ‘Ideal’ because

  • It is based on variable weights.
  • It takes into consideration the price and quantities of both the base year and current year.
  • It is based on Geometric Mean (GM) which is regarded as the best mean for calculating index number.
  • Fisher’s index number satisfies both the Time Reversal Test and Factor Reversal Test.

Consumer Price Index or Cost of Living Index Number
The consumer price index is the index number which measures the averages change in prices paid by the specific class of consumers for goods and services consumed by them in the current year in comparison with base year.

Construction of Consumer Price Index

  • Selection of the consumer class
  • Information about the family budget
  • Choice of base year
  • Information about prices
  • Weightage – There are two ways of according weights
    • Quantity weight
    • Expenditure weight

The following formula is used to find consumer’s price index
Consumer Price Index (CPI) = ΣWRΣW

Wholesale Price Index (WPI)
The Wholesale Price Index (WPI) measures the relative changes in the prices of commodities traded in the wholesale markets. In India, the wholesale price index numbers are constructed on weekly basis.

Industrial Production Index
The index number of industrial production measures changes in the level of industrial production comprising many industries. It includes the production of the public and the private sector. It is a weighted average of quantity relatives. The formula for the index is
P01=Σq1×WΣW×100

Construction of Index Number of Industrial Production

  • Classification of industries
  • Statistics or data related to industrial production
  • Weightage

Agricultural Production Index
Index number of agricultural production is weighted average of quantity relatives.

Sensex
Sensex is the index showing changes in the Indian stock market. It is a short form of a Bombay Stock Exchange sensitive index. It is constructed with 1978-79 as the reference year or the base year. It consists of 30 stocks of leading companies in the country.

Purpose of Constructing Index Number

  • Purpose of constructing index number of prices is to know the relative change or percentage in the price level over time. A rising general price level over time is a pointer towards inflation, while a falling general price level over time is a pointer towards deflation.
  • Purpose of constructing index number of quantity is to know relative change or percentage change in the quantum or volume of output of different goods and services. A rising index of quantity suggests a rising level of economic activity and vice-versa.
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 Chapter 7 Correlation | class 11th | ncert quick revision notes Statistics for Economics

Statistics for Economics Class 11 Notes Chapter 7 Correlation

Correlation
It is a statistical method or a statistical technique that measures quantitative relationship between different variables, like between price and demand.
According to Croxton and Cowden, “When the relationship is of a quantitative nature, the appropriate statistical tool for discovering and measuring the relationship and expressing it in a brief formula is known as correlation.”

Types of Correlation
Correlation is commonly classified into negative and positive correlation.

  • Positive Correlation When two variables move in the same direction, such a relation is called positive correlation, e.g., Relationship between price and supply
  • Negative Correlation When two variables changes in different directions, it is called negative correlation. Relationship between price and demand.

Degree of Correlation
Degree of correlation refers to the coefficient of correlation
Statistics for Economics Class 11 Notes Chapter 7 Correlation 1
(ii) Absence of Correlation
(iii) Limited Degree of correlation
The degree of correlation between 0 and 1 may be rated as

  • High (0.75 and 1)
  • Moderate (0.25 and 0.75)
  • Low (0 and 0.25)

Methods of Estimating Correlation
(i) Scatter Diagram Scattered diagram offers a graphic expression of the direction and degree of correlation.
Statistics for Economics Class 11 Notes Chapter 7 Correlation 2

Karl Pearson’s Coefficient of Correlation
This is also known as product moment correlation and simple correlation coefficient.
Karl Pearson has given a quantitative method of calculating correlation Karl Pearson’s coefficient correlation is generally written as V.
Formula According to Karl Pearson’s method, the coefficient of correlation is measured as
r=ΣxyNσxσy
Where,
r = Coefficient of correlation;
x = x – x¯¯¯
y= y – y¯¯¯
σx = Standard deviation of x series
σy = Standard deviation of y series
N= Number of observations
If there is no need to calculate standard deviation of x and y directly using the following formula
r=ΣxyΣx2×Σy2√
Here, x(x – x¯¯¯), y = (y – y¯¯¯)

Short-cut Method
This method is used when mean value is not in whole number but in fractions. In this method, deviation is calculated by taking the assumed mean both the series.
Coefficient of correlation is calculated using the following formula
Statistics for Economics Class 11 Notes Chapter 7 Correlation 3
Here, dx = deviation of x series from the assumed mean = (x – A)
dy = deviation of y series from the assumed mean = (y – A)
Σ dxdy – sum of the multiple of dx and dy
Σ dx2 = sum of square of dx
Σ dy2 = sum of square of dy
Σdx= sum of deviation of x-series
Σdy = sum of deviation of y-series
N = Total number of items

Step Deviation Method
Coefficient of correlation is calculated using the following formula
Statistics for Economics Class 11 Notes Chapter 7 Correlation 4

Spearman’s Rank Correlation Coefficient
In 1904, ‘Charles Edwards Spearman’ developed a formula to calculate coefficient correlation of qualitative variables. It is popularly known as Spearman’s rank. Difference formula or method.
Statistics for Economics Class 11 Notes Chapter 7 Correlation 5

Coefficient of Rank Correlation when Ranks are Equal formula
Statistics for Economics Class 11 Notes Chapter 7 Correlation 6
Here, m = number of items of equal ranks.

Importance or Significance of Correlation

  • The study of correlation shows the direction and degree of relationship between the variables.
  • Correlation coefficient some times suggests cause and effect relationship.
  • Correlation analysis facilitates business decisions because the trend path of one variable may suggest the expected changes in the other.
  • Correlation analysis also helps policy formulation.
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 Chapter 6 Measures of Dispersion | class 11th | ncert quick revision notes Statistics for Economics

Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion

Dispersion
“It is the measure of the variation of the item”. According to Spiegel, ‘The degree to which numerical data tend to spread about an average value is called the variation or dispersion of the data”.
Different methods of measuring dispersion are

  • Range
  • Quartile deviation
  • Mean deviation
  • Standard deviation

Range Range is the difference between the highest value and the lowest value in a series.
R = H – L or L – S
H or L = Highest or Largest value of series
L or S = Lowest or Smallest value of series

Coefficient of range = H−LH+L or L−SL+S
Calculation of Range and Coefficient of Range
(i) Individual Series and Discrete Series
Range = H – L or L – S
Coefficient of Range = H−LH+L or L−SL+S

(ii) Frequency Distribution Series

  • Mid values of the class interval are found, difference between the highest and lowest values would be the range.
  • According to this method, we find the difference between lower limit of the first class interval and upper limit of the last class interval in the series would be the range.

(iii) Inter Quartile Range
Difference between third quartile ( Q3) and first quartile of a series, is called Inter quartile range.
IQR = Q3 – Q1

Quartile Deviation
Quartile deviation is half of inter quartile range.
QD = Q3−Q12
It is also called semi-inter quartile range.
(i) Coefficient of Quartile Deviation (Coefficient of QD)
Coefficient of QD = Q3−Q1Q3+Q1
(ii) Calculation of Quartile Deviation
(a) Individual Series and Discrete Series First find out Q1 and Q3 from the following equations
Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion 1
(b) Frequency Distribution
Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion 5

Mean Deviation
“Mean deviation is the arithmetic average of deviation of all the values taken from a statistical average of series. In taking deviation of values, algebraic signs + and – are not taken into consideration, that is negative deviations are also treated as positive deviations”.
(i) Formulas for Mean Deviation
(a) If deviations are taken from median, the following formula is used
Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion 4
(b) If deviation are taken from arithmetic mean of the series
Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion 3

(ii) Coefficient of Mean Deviation

  • Coefficient of mean deviation from Mean = MDX¯¯¯X¯¯¯¯¯
  • Coefficient of MD from Median = MDMM
  • Coefficient of MD from Mode = MDZZ

(iii) Calculation of Mean Deviation or Coefficient of Mean Deviation
(a) Individual Series
Estimating MD through Median, MD = Σ|dM|N
Estimating MD through Mean, MD = Σ|dX¯¯¯¯¯|N
Estimating Coefficient of MD through Median Coefficient of MD = MDMM
Estimating Coefficient of MD through Mean Coefficient of MD = MDX¯¯¯X¯¯¯¯¯

(b) Discrete Series
Estimating MD through median, MDM = Σf|dm|N
Estimating MD through mean, MDX¯¯¯¯¯ = Σf|dX¯¯¯¯¯|N
Estimating Coefficient of MD through Median Coefficient of MD = MDMN
Estimating Coefficient of MD through Median Coefficient of MD = MDX¯¯¯X¯¯¯¯¯

(c) Frequency Distribution Series
Mean deviation from Median, MDM = Σf|dM|Σf
Coefficient of MD = MDMM
Mean deviation from Mean, MDX¯¯¯¯¯ = Σf|dX¯¯¯¯¯|Σf
Coefficient of MD = MDX¯¯¯X¯¯¯¯¯

Standard Deviation
Standard deviation is the square root of the arithmetic mean of the squares of deviations of the items from their mean values.

Coefficient of Standard Deviation
This is a relative measure of the dispersion of series.
Coefficient of standard deviation (Coefficient of σ) = σX¯¯¯¯¯
(i) Calculation of Standard Deviation
(a) Direct Method
Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion 6
Here, σ = Standard Deviation;
ΣX2 = Sum total of the squares of deviation,
X¯¯¯¯ = Mean Value,
X−X¯¯¯¯ = Deviation from mean value;
N = number of items
(b) Short-cut Method
Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion 7
(c) Step Deviation Method
Statistics for Economics Class 11 Notes Chapter 6 Measures of Dispersion 8

(ii) Calculation of Coefficient of Variation
(a) Individual series = σX × 100
(b) Discrete series = σX × 100
(c) Frequency distribution series = σX × 100

Lorenz Curve
It is a curve that shows deviation of actual distribution from the showing equal distribution.
(i) Construction of the Lorenz Curve

  • Calculate class mid-points
  • Calculate cumulative frequencies as in column 6
  • Express the grand total of column 3 and 6 as 100 and convert the cumulative totals in these columns in to percentage.
  • Now, on the graph paper, take the cumulative percentage of the variable on Y-axis and cumulative percentages of X-axis.
  • Draw a line joining co-ordinate (0, 0) with (100,100) this is called the line of equal distribution.
  • Plot the cumulative percentages of the variable with cumulative percentages of frequency.
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 Chapter 5 Measures of Central Tendency | class 11th | ncert quick revision notes Statistics for Economics

Statistics for Economics Class 11 Notes Chapter 5 Measures of Central Tendency

Central Tendency
A central tendency refers to a central value or a representative value of a statistical series.
According to Clark, “An average is a figure that represents the whole group”.

Types of Statistical Averages
Averages are broadly classified into two categories

  • Mathematical Averages
  • Positional Averages

Arithmetic Mean
Arithmetic Mean is the number which is obtained by adding the values of all the items of a series and dividing the total by the number of items.
Arithmetic Mean is generally written as X. It may be expressed in the form of following formula
X¯¯¯¯=x1+x2+x3+……xNN or ΣX¯¯¯¯¯N

Types of Arithmetic Mean

  • Simple Arithmetic Mean
  • Weighted Arithmetic Mean

Methods of Calculating Simple Arithmetic Mean
(i) Individual Series In the case of individual series, Arithmetic Mean may be calculated by two methods

  • Direct Method According to this method, we find the Arithmetic mean from the following formula
    X¯¯¯¯=ΣXN or X¯¯¯¯= Total value of the item  Number of items 
  • Short-cut Method By short cut method, we find the Arithmetic Mean from the following formula
    X¯¯¯¯=A+ΣdN
    Here, X¯¯¯¯ = Arithmetic Mean, A = Assumed average of Ed = Net sum of the deviations of the different values from the assumed average; and N = Number of items in the series,

(ii) Discrete Series There are three methods of calculating mean of the discrete series

  • Direct Method Direct method of estimating mean of the discrete frequency series uses the formula
    X¯¯¯¯=ΣfXΣf
  • Short-cut Method Short cut method of estimating mean of the discrete frequency series uses the following formula
    X¯¯¯¯=A+ΣfdΣf
  • Step-deviation Method This method is a variant of short-cut method. It is adopted when deviations from the assumed mean have some common factor
    X¯¯¯¯=A+ΣfdΣf×c

(iii) Frequency Distribution
There are three methods of calculating mean in frequency distribution
(a) Direct Method Direct method of estimating mean of the discrete frequency series uses the formula
X¯¯¯¯=ΣfmΣf
m = mid-value, mid-value = L1+L22
L1 = lower limit of the class
L2 = upper limit of the class
(b) Short-cut Method Short cut method of estimating mean of the frequency distribution uses the formula
X¯¯¯¯=A+ΣfdΣf
(c) Step Deviation Method According to this method, we find the Arithmetic Mean by the following formula
X¯¯¯¯=A+Σfd′Σf×c
(d) Weighted Arithmetic Mean It is the mean of weighted items of the series. Different items are accorded different weights depending on their relative importance. The weighted sum of the items is divided by the sum of the weights.

Calculation of Weighted Mean
According to this way, we find weighted mean from the following information
X¯¯¯¯W=ΣWXΣW
(i) Merits

  • Simplicity
  • Certainty
  • Based on all items
  • Algebraic treatment
  • Stability
  • Basis of comparison
  • Accuracy test

(ii) Demerits

  • Effect of extreme value
  • Mean value may not figure in the series at all
  • Laughable conclusions
  • Unsuitability
  • Misleading conclusions

Median
“The Median is that value of the variable which divides the group into two equal parts, one part comprising all values greater than the Median value and the other part comprising all the values smaller than the Median value”.
(i) Calculation of Median
(a) Individual Series Calculation of Median in individual series involves the following formula
M = Size of (N+12)th item
When N of the series is an even number, Median is estimated using the following formula
Statistics for Economics Class 11 Notes Chapter 5 Measures of Central Tendency 1
(b) Discrete Series Calculation of Median in case of discrete series or frequency array involves the following formula
M = Size of (N+12)th item
(c) Frequency Distribution Series
The following formula is applied to determine the Median Value
Statistics for Economics Class 11 Notes Chapter 5 Measures of Central Tendency 2

Quartiles
If a statistical series is divided in to four equal parts, the end value of each part is called a Quartile.
(i) Calculation of Quartiles Quartile values (Q1 and Q3) are estimated differently for different sets of series,
(a) Individual and Discrete Series
Statistics for Economics Class 11 Notes Chapter 5 Measures of Central Tendency 3
(b) Frequency Distribution Series In frequency distribution series, the class interval of Q1 and Q3 are first identified as under
Statistics for Economics Class 11 Notes Chapter 5 Measures of Central Tendency 4

Percentiles
Percentiles divide the series into 100 equal parts, and is generally expressed as P.
Percentiles are estimated for different types of series as under
(i) Individual and Discrete Series
Statistics for Economics Class 11 Notes Chapter 5 Measures of Central Tendency 5
(ii) Frequency Distribution Series
Statistics for Economics Class 11 Notes Chapter 5 Measures of Central Tendency 6

Mode
The value of the variable which occurs most frequently in a distribution is called the mode.
According to Croxton and Cowden, “ The mode may be regarded as the most typical of a series of value”.
(i) Calculation of Mode

  • Individual Series There are two ways of calculating Mode in individual series
    • By inspection
    • By converting individual series into discrete series
  • Discrete Series There are two methods for calculation of mode indiscrete frequency series
    • Inspection Method
    • Grouping Method
  • Frequency Distribution Series The exact value of Mode can be calculated with the following formula
    Z=L1+f1−f02f1−f0−f2xi

Relative Position of Arithmetic Mean, Median and Mode Suppose we express,
Arithmetic Mean = Me
Median = Mi
Mode = Mo
The relative magnitude of the three are Me > Mi > Mo or Me < Mi < Mo The Median is always between the Arithmetic Mean and the Mode.

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Chapter 4 Presentation of Data | class 11th | ncert quick revision notes Statistics for Economics

Statistics for Economics Class 11 Notes Chapter 4 Presentation of Data

Textual Presentation
In textual presentation, data are a part of the text of study or a part of the description of the subject matter of study.

Tabular Presentation of Data
“Tabulation involves the orderly and systematic presentation of numerical data in a form designed to elucidate the problem under consideration”

Components of a Table
Following are the principal components of a table

  • Table number
  • Title
  • Head note
  • Stubs
  • Caption
  • Body or field
  • Footnotes
  • Source

Classification of Data and Tabular Presentation
(i) Qualitative Classification of Data and Tabular Presentation Qualitative classification occurs when data are classified on the basis of qualitative attributes or qualitative.

(ii) Characteristics of a Phenomenon

  • Quantitative Classification of Data These occurs when data are classified on the basis ot quantitative characteristics of a phenomenon.
  • Temporal Classified of Data In this, data are classified according to time, and time becomes the classifying variable.

(iii) Spatial Classification In spatial classification place, location becomes the classifying variable. It may be a village, a town, a district, etc.
(iv) Merits of Tabular Presentation

  • Simple and brief presentation
  • Facilitates comparison
  • Easy analysis
  • High lights characteristics of data
  • Economical

Diagrammatic Presentation of Data
These translates quite effectively the highly abstract ideas contained in numbers into more concrete and easily comprehensible form. Diagrammatic presentation is classified as given below
(i) Bar Diagrams Bar diagrams are these diagrams in which data are presented in the form of bars or rectangles. Types of Bar Diagram are as follows

  • Simple Bar Diagrams Simple bar diagrams are those diagrams which are based on a single set of numerical data.
  • Multiple Bar Diagrams These are those diagram which show two or more sets of data simultaneously.
  • Sub Divided Bar Diagram Sub-divided bar diagram are those diagrams which simultaneously present total values as well as part values of a set of data.
  • Percentage Bar Diagram Percentage bar diagrams are those diagrams which show simultaneously, different parts of the values of a set of data in terms of percentages.

(ii) Pie or Circular Diagrams Pie diagram is a circle divided into various segments showing the per cent values of a series. This diagram does not show absolute values.
(iii) Frequency Diagram Data in the form of grouped frequency distributions are generally represented by frequency diagram like histogram, frequency polygon, frequency curve and ogive.

  • Histogram A histogram is a two dimensional diagram. It is a set of rectangles with passes as the intervals between class boundaries and with areas proportional to the class frequency
    Histogram frequency distribution are of two types
    • Histogram of equal class intervals
    • Histogram of unequal class intervals
  • Polygon Polygon is another form of diagrammatic presentation of data. It is formed by joining mid points of the tops of all rectangles in a histogram. However, a polygon can be drawn even without constructing a histogram.
  • Frequency Curve A frequency curve is a curve which is plotted by joining the mid points of all tops of histogram by free hand smoothed curves and not by straight lines.
  • Ogive or Cumulative Curve Ogive or cumulative curve is the curve which is constructed by plotting cumulative frequency data on the group paper, in the form of a smooth curve.
    A cumulative frequency curve or ogive may be constructed in two ways
    • Less than Method In this method, beginning from upper limit of the 1st values we go on adding the frequencies corresponding to every next upper limit of the series.
    • More than Method In this method, we take cumulative total of the frequencies beginning with lower limit of the 1st class interval.

(iv) Arithmetic Line Graph An arithmetic line graph is also called time series graph. In it time is plotted along x-axis and the value of the variable along y-axis. A line graph by joining these plotted points, these obtained is called time series graph.

Rules for Constructing a Graph

  • Choice of scale
  • Proportion of axis
  • Method of plotting the points
  • Lines of different types
  • Table of data
  • Use of false line
  • To draw a line or curve
    • One Variable Graph One variable graph are those graphs in which values of only one variable are shown with respect to some time period.
    • Two or More than Two Variable Graphs These – are the graphs in which values of two variables are simultaneously shown with respect to some period of time.

Merits of Diagrammatic and Graphic Presentation

  • Simple and understandable information
  • Lasting impact
  • No need of training or specialised knowledge
  • Attractive and effective means of presentation
  • A quick comparative glance
  • Information and entertaining
  • Location of averages
  • Study of correlation

Limitations of Diagrammatic and Graphic Presentation

  • Limited use
  • Misuse
  • Only preliminary conclusions
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Chapter 3 Organisation of Data | class 11th | ncert quick revision notes Statistics for Economics

Statistics for Economics Class 11 Notes Chapter 3 Organisation of Data

Organisation of Data
Organisation of data refers to the arrangement of figures in such a form that comparison of the mass of similar data may be facilitated and further analysis may be possible.

Classification
Classification is the process of arranging things in groups or classes according to their resemblances and affinities and gives expression to the unity of attributes that may exist amongst a diversity of individuals.

Objectives of Classification

  • Simplification and Briefness
  • Utility
  • Distinctiveness
  • Comparability
  • Scientific arrangement
  • Attractive and effective

Characteristic of a Good Classification

  • Comprehensiveness
  • Clarity
  • Homogeneity
  • Suitability
  • Stability
  • Elastic

Basis of Classification

  • Geographical Classification This classification of data is based on the geographical or locational differences of the data.
  • Chronological Classification When data are classified on the basis of time, it is known as chronological classification.
  • Qualitative Classification This classification is according to qualities or attributes of the data.
    This classification may be of two types
    • Simple classification
    • Manifold classification
  • Quantitative or Numerical Classification Data are classified in to classes or groups on the basis of their numerical values. Quantitative classification is also called classification by variables.
  • Concept of Variable A characteristic or a phenomenon which is capable of being measured and changes its value overtime is called a variable.
    The variable may be either discrete or continuous
    • Discrete Variable These are those variables that increase in jumps or in compete numbers.
    • Continuous Variable Variable that assume a range of values or increase not in jumps but continuously or in fractions are called continuous variables.
  • Raw Data A mass of data in its crude form is called raw data.

Types of Statistical Series Statistical series are of two types

  • Individual Series These are those series in which the items are listed singly. These series may be presented in two ways
    • According to serial numbers
    • Ascending or descending order of data
  • Frequency Series Frequency series may be of two types
    • Discrete Series or Frequency Array It is that series in which data are presented in way that exact measurement of items are clearly shown. In this series there are no class intervals and a particular item in the series.
    •  Frequency Distribution It is that series in which items cannot be exactly measured. The items assume a range of values and are placed within the limits is called class interval.

Frequency distribution is also known as continuous series or series with class-intervals, or series of grouped data.

Types of Frequency Distribution

  • Exclusive Series It is that series in which every class-interval excludes items corresponding to its upper limit.
  • Inclusive Series An inclusive series is that series which includes all items upto its upper limit.
  • Open End Series An open end series is that series in
    which lower limit of the first class-interval and the upper limit of last class- interval is missing like as below – 5, 20 and above
  • Cumulative Frequency Series It is that series in which the frequencies are continuously added corresponding to each class-interval in the series.
    There are two ways of converting this series into cumulative frequency series
    • Cumulative frequencies may be expressed on the basis of upper class limits of the class-intervals.
    • Cumulative frequencies may b expressed on the basis of lower class limits of the class-intervals.
  • Mid Values Frequency Series Mid value frequency series are those series in which we have only mid values of the class intervals and the corresponding frequencies.
  • Univariate Distribution The frequency distribution of a single variable is called a univariate distribution.
  • Bivariate Distribution A bivariate distribution is the frequency distribution of two variables.
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