Question

In the following data, find the values of p and q. Also, find the median class and modal class.

Class	Frequency (f)	Cumulative frequency (cf)
100 – 200	11	11
200 – 300	12	p
300 – 400	10	33
400 – 500	q	46
500 – 600	20	66
600 – 700	14	80

Answer 1

Here, 𝑝=11+12=23
And 33+𝑞=46
⟹ 𝑞=46−33
= 13
Thus, p is 23 and q is 13.
Now,
Here the maximum class frequency is 20, and the class corresponding to this frequency is 500-600.
So, the modal class is 500-600.
Also, Σ 𝑓=𝑁= 80
⟹` N/2 = 40.`
The cumulative frequency just greater than 40 is 46, and the corresponding class is 400-500.
Thus, the median class is 400-500.