Question

The class marks of a frequency distribution are as follows :
15, 20, 25, ...

0Find the class corresponding to the class mark 20.

Explain with complete steps & justifications to solve any such questions.

Answer 1

Difference between class marks = 5

And

5 = 2 .5
Respectively, the classes for these class marks are as follows:

2.5 - 7.5

7.5 - 12.5

12.5 - 17.5

17.5 - 22.5

22.5 - 27.5
Hence, the class corresponding to class mark 20 = 17.5 - 22.5 hope it's help you

Answer 2

class marks are -
15, 20, 25

STEPS -
1) take out the difference between the given corresponding class marks

the difference between the class marks
= 20- 15
= 5

2) find the mid value of the difference.

now 5/2 = 2.5

3) add and subtract the midvalue with the class mark to obtain the upper and lower class limits.

of the class corresponding to class mark 20:-
upper limit = 20 + 2.5 = 22.5
lower limit = 20 - 2.5 = 17.5
___________________________

therefore
required class = 17.5 - 22.5