CBSE Class 10-Mathematics: Chapter –14 Statistics Part 15

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Question 11:

Following table shows the daily pocket allowances given to the children of a multi-story building. The mean of the pocket allowances is . Find out the missing frequency.

Following table shows the daily pocket allowances given to the children of a multi-story building. The mean of the pocket allowances is Rs. 18. Find out the missing frequency

Class Interval

Frequency

Answer:

Let the missing frequency , we have

Following table shows the daily pocket allowances given to the children of a multi-story building. The mean of the pocket allowances is Rs. 18. Find out the missing frequency

Class interval

Mid-value

11-13

3

12

-3

-9

13-15

6

14

-2

-12

15-17

9

16

-1

-9

17-19

13

18

0

0

19-21

f

20

1

F

21-32

5

22

2

10

23-25

4

24

3

12

Let assumed mean , Here

We know that mean

Hence, missing frequency

Question 12:

A survey regarding the heights (in cm) of girls of Class of a school was conducted and the following data was obtained. Find the median height.

Find the median height

Height (in cm)

No. of girls

Less than 140

Less than 145

Less than 150

Less than 155

Less than 160

Less than 165

Answer:

We have,

Find the median height

Class Intervals

Frequency (f)

C.F

Below

Here, which is in the class

Here,

Median height of the girls