RD SHARMA SOLUTION CHAPTER -24 Measures of Central Tendency| CLASS 9TH MATHEMATICS-EDUGROWN

Chapter 24 – Measures of Central Tendency Exercise Ex. 24.1

Question 1

Solution 1

Question 2

Solution 2

Question 3

Solution 3

Question 4

Solution 4

Question 5

Solution 5

Question 6

Solution 6

Question 7Find the mean of first five multiples of 3.Solution 7

Question 8

Solution 8

Question 9

Solution 9

Question 10

The numbers of children in 10 families of a locality are:

2, 4, 3, 4, 2, 0, 3, 5, 1, 1, 5. Find the mean number of children per family.Solution 10

Question 11

Solution 11

Question 12

Solution 12

Question 13

The traffic police recorded the speed (in km/hr) of 10 motorists as 47, 53, 49, 60, 39, 42, 55, 57, 52, 48. Later on an error in recording instrument was found. Find the correct average speed of the motorists if the instrument recorded 5 km/hr less in each case.Solution 13

Question 14

Solution 14

Question 15

Solution 15

Question 16

Solution 16

Question 17

Solution 17

Question 18

Solution 18

Question 19

If M is the mean of x₁, x₂, x₃, x₄, x₅ and x₆ , prove that

(x₁ – M) + (x₂ – M) + (x₃ -M) + (x₄ – M) + (x₅ – M) + (x₆ – M) = 0Solution 19

Question 20

Solution 20

Question 21

Solution 21(i)

(ii)

Question 22

Solution 22

Question 23

Solution 23

Question 24

Solution 24

Chapter 24 – Measures of Central Tendency Exercise Ex. 24.2

Question 1

Solution 1

Question 2

Solution 2

Question 3

Solution 3

Question 4

Five coins were simultaneously tossed 1000 times and at each toss the number of heads were observed. The number of tosses during which 0, 1, 2, 3, 4 and 5 heads were obtained are shown in the table below. Find the mean number of heads per toss.

No. of heads per toss	No. of tosses
0 1 2 3 4 5	38 144 342 287 164 25
Total	1000

Solution 4

Question 5

Solution 5

Question 6

Solution 6

Question 7

Solution 7

Question 8

Solution 8

Question 9

Solution 9

Question 10

Solution 10

Question 11

Solution 11

Question 12

Solution 12

x	f	xf
10	17	170
30	f1	30f1
50	32	1600
70	f2	70f2
90	19	1710
	N = 120

Chapter 24 – Measures of Central Tendency Exercise Ex. 24.3

Question 1

Solution 1

Question 2

Solution 2

Question 3

Solution 3

Question 4

Solution 4

Question 5

Solution 5

Question 6

Solution 6

Question 7

Solution 7

Question 8

Solution 8

Question 9Numbers 50, 42, 35, 2x + 10, 2x – 8, 12, 11, 8 are written in descending order and their median is 25, find x.Solution 9

Question 10

Solution 10

Question 11

Solution 11

Question 12

Solution 12

Question 13The following observations have been arranged in ascending order. If the median of the data is 63, find the value of x.
    29,    32,    48,    50,    x,    x + 2,    72,    78,    84,    95    

Solution 13

Chapter 24 – Measures of Central Tendency Exercise Ex. 24.4

Question 1

Solution 1

Question 2

Solution 2

Question 3

Solution 3

Question 4(i)Find the mode of        14,      25,    14,    28,    18,    17,    18,    14,    23,    22,    14,    18Solution 4(i)Arranging the data in an ascending order 14, 14, 14, 14, 17, 18, 18, 18, 22, 23, 25, 28  Here observation 14 is having the highest frequency i.e. 4 in given data. So, mode of given data is 14.  

Question 4 (ii)

Solution 4 (ii)

Question 5

The demand of different sizes, as obtained by a survey, is given below:

Size	38	39	40	41	42	43	44	Total
Number of persons (wearing it):	26	39	20	15	13	7	5	125

Find the modal shirt size, as observed from the survey.Solution 5