In This Post we are providing Chapter -15 |STATISTICS |NCERT Solutions for Class 11 Maths which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These Class 11 can be really helpful in the preparation of STATISTICS Board exams and will provide you with in depth detail of the chapter.
We have solved every question stepwise so you don’t have to face difficulty in understanding the solutions. It will also give you concepts that are important for overall development of students. Class 11 Maths STATISTICS NCERT Written Solutions will be useful in higher classes as well because variety of questions related to these concepts can be asked so you must study and understand them properly.
Find the mean deviation about the mean for the data in Exercises 1 and 2.
Ex 15.1 Class 11 Maths Question 1.
4, 7, 8, 9, 10, 12, 13, 17
Solution:
Mean of the given data is
Ex 15.1 Class 11 Maths Question 2.
38, 70, 48, 40, 42, 55, 63, 46, 54, 44
Solution:
Mean of the given data is
Ex 15.1 Class 11 Maths Question 3.
13, 17, 16, 14, 11, 13, 10, 16, 11, 18, 12, 17
Solution:
Arranging the data in ascending order, we have
10, 11, 11, 12, 13, 13, 14, 16, 16, 17, 17, 18
Here n = 12 (which is even)
So median is the average of 6th and 7th observations
Ex 15.1 Class 11 Maths Question 4.
36, 72, 46, 42, 60, 45, 53, 46, 51, 49
Solution:
Arranging the data in ascending order, we have 36, 42, 45, 46, 46, 49, 51, 53, 60, 72
Here n = 10 (which is even)
So median is the average of 5th and 6th observations
Find the mean deviation about the mean for the data in Exercises 5 and 6.
Ex 15.1 Class 11 Maths Question 5.
Solution:
Ex 15.1 Class 11 Maths Question 6.
Solution:
Find the mean deviation about the median for the data in Exercises 7 and 8.
Ex 15.1 Class 11 Maths Question 7.
Solution:
Ex 15.1 Class 11 Maths Question 8.
Solution:
Find the mean deviation about the mean for the data in Exercises 9 and 10.
Ex 15.1 Class 11 Maths Question 9.
Solution:
Ex 15.1 Class 11 Maths Question 10.
Solution:
Ex 15.1 Class 11 Maths Question 11.
Find the mean deviation about median for the following data:
Solution:
Ex 15.1 Class 11 Maths Question 12.
Calculate the mean deviation about median age for the age distribution of 100 persons given below:
[Hint: Convert the given data into continuous frequency distribution by subtracting 0.5 from lower limit and adding 0.5 to the upper limit of each class interval]
Solution:
We hope the NCERT Solutions for Class 11 Maths Chapter 15 Statistics Ex 15.1 help you. If you have any query regarding NCERT Solutions for Class 11 Maths Chapter 15 Statistics Ex 15.1, drop a comment below and we will get back to you at the earliest.
Find the mean and variance for each of the data in Exercises 1 to 5.
Ex 15.2 Class 11 Maths Question 1.
6, 7, 10, 12, 13, 4, 8, 12
Solution:
Here xi = 6, 7, 10, 12, 13, 4, 8, 12
∴ Σxi = 6 + 7 + 10 + 12 + 13 + 4 + 8 + 12 = 72
n = 8
Ex 15.2 Class 11 Maths Question 2.
First n natural numbers
Solution:
Here xi = 1, 2, 3, 4, ……….n
Ex 15.2 Class 11 Maths Question 3.
First 10 multiples of 3
Solution:
Here xi = 3, 6, 9, 12, 15, 18, 21, 27, 30,
Σxi = 3 + 6 + 9 + 12 + 15 + 18 + 21 + 24 + 27 + 30 = 165
n = 10
Ex 15.2 Class 11 Maths Question 4.
Solution:
Ex 15.2 Class 11 Maths Question 5.
Solution:
Ex 15.2 Class 11 Maths Question 6.
Find the mean and standard deviation using short-cut method
Solution:
Find the mean and variance for the following frequency distributions in Exercises 7 and 8.
Ex 15.2 Class 11 Maths Question 7.
Solution:
Ex 15.2 Class 11 Maths Question 8.
Solution:
Ex 15.2 Class 11 Maths Question 9.
Find the mean, variance and standard deviation using short-cut method.
Solution:
Ex 15.2 Class 11 Maths Question 10.
The diameters of circles (in mm) drawn in a design are given below:
Calculate the standard deviation and mean diameter of the circles.
[Hint: First make the data continuous by making the classes as 32.5 – 36.5, 36.5 – 40.5, 40.5 – 44.5, 44.5 – 48.5, 48.5 – 52.5 and then proceed.]
Solution:
We hope the NCERT Solutions for Class 11 Maths Chapter 15 Statistics Ex 15.2 help you. If you have any query regarding NCERT Solutions for Class 11 Maths Chapter 15 Statistics Ex 15.2, drop a comment below and we will get back to you at the earliest.
Ex 15.3 Class 11 Maths Question 1.
From the data given below state which group is more variable, A or B?
Solution:
For Group A :
Ex 15.3 Class 11 Maths Question 2.
From the prices of shares X and Y below, find out which is more stable in value:
Solution:
Ex 15.3 Class 11 Maths Question 3.
An analysis of monthly wages paid to workers in two firms A and B, belonging to the same industry, gives the following results:
(i) Which firm A or B pays larger amount as monthly wages?
(ii) Which firm, AorB, shows greater variability in individual wages?
Solution:
(i) Firm A :
Number of wage earners (n1) = 586
Mean of monthly wages (
∴ Total monthly wages = 5253 x 586
= Rs. 3078258
Firm B :
Number of wage earners (n2) = 648
Mean of monthly wages (
∴ Total monthly wages = 5253 x 648
= Rs. 3403944
Hence, Firm B pays larger amount as monthly wages.
(ii) Since both the firms have same mean of monthly wages, so the firm with greater variance will have more variability in individual wages. Thus firm B will have more variability in individual wages.
Ex 15.3 Class 11 Maths Question 4.
The following is the record of goals scored by team A in a football session:
For the team B, mean number of goals scored per match was 2 with a standard deviation 1.25 goals. Find which team may be considered more consistent?
Solution:
For team A:
Ex 15.3 Class 11 Maths Question 5.
The sum and sum of squares corresponding to length x (in cm) and weight y (in gm) of 50 plant products are given below:
Which is more varying, the length or weight?
Solution:
We hope the NCERT Solutions for Class 11 Maths Chapter 15 Statistics Ex 15.3 help you. If you have any query regarding NCERT Solutions for Class 11 Maths Chapter 15 Statistics Ex 15.3, drop a comment below and we will get back to you at the earliest.
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