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

Doorsteptutor material for CBSE is prepared by world's top subject experts: fully solved questions with step-by-step explanation- practice your way to success.

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