## RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency Ex 24.2

These Solutions are part of RD Sharma Class 9 Solutions. Here we have given RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency Ex 24.2

Other Exercises

- RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency Ex 24.1
- RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency Ex 24.2
- RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency Ex 24.3
- RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency Ex 24.4
- RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency VSAQS
- RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency MCQS

Question 1.

Calculate the mean for the following distribution

x 5 6 7 8 9

f 4 8 14 11 3

Solution:

Question 2.

Find the mean of the following data:

x 19 21 23 25 27 29 31

f 13 15 16 18 16 15 13

Solution:

Question 3.

Find the mean of the following distribution:

x 10 12 20 25 35

f 3 10 15 7 5

Solution:

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.

Solution:

Question 5.

The mean of the following data is 20.6. Find the value of p.

x 10 15 p 25 35

f 3 10 25 7 5

Solution:

Mean = 20.6

Question 6.

If the mean of the following data is 15, find p?.

x 5 10 15 20 25

f 6 p 6 10 5

Solution:

Mean = 15

Question 7.

Find the value of p for the following distribution whose mean is 16.6.

x 8 12 15 p 20 25 30

f 12 16 20 24 16 8 4

Solution:

Mean = 16.6

Question 8.

Find the missing value of p for the following distribution whose mean is 12.58.

x 5 8 10 12 p 20 25

f 2 5 8 22 7 4 2

Solution:

Mean = 12.58

Question 9.

Find the missing frequency (p) for the following distribution whose mean is 7.68.

x 3 5 7 9 11 13

f 6 8 15 p 8 4

Solution:

Mean = 7.68

Question 10.

Find the value of p, if the mean of the following distribution is 20.

x 15 17 19 20 + p 23

f 2 3 4 5p 6

Solution:

Mean = 20

Question 11.

Candidates of four schools appear in a mathematics test. The data were as follows:

If the average score of the candidates of all the four schools is 66, find the number of candidates that appeared from school III.

Solution:

Let number of candidates in school III = p

Then total number of candidates in 4 schools = 60 + 48 + p + 40 = 148 + p

Average score of 4 schools = 66

∴Total score = (148 + p) x 66

Now mean score of 60 in school I = 75 .

∴Total = 60 x 75 = 4500

In school II, mean of 48 = 80

∴Total = 48 x 80 = 3840

In school III, mean of p = 55

∴Total = 55 x p = 55p

and in school IV, mean of 40 = 50

∴Total = 40 x 50 = 2000

Now total of candidates of 4 schools = 148 + p

and total score = 4500 + 3840 + 55p + 2000 = 10340 + 55p

∴10340 + 55p = (148 + p) x 66 = 9768 + 66p

=> 10340 – 9768 = 66p – 55p

=> 572 = 11p

∴ p = \(\frac { 572 }{ 11 } \)

Number of candidates in school III = 52

Question 12.

Find the missing frequencies in the following frequency distribution if it is known that the mean of the distribution is 50.

x 10 30 50 70 90

f 17 f1 32 f1 19

Total 120

Solution:

Mean = 50

Hope given RD Sharma Class 9 Solutions Chapter 24 Measures of Central Tendency Ex 24.2 are helpful to complete your math homework.

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