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 (c f)
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, = 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 

⇒ \(\frac{N}2\) = 40. 

The cumulative frequency just greater than 40 is 46, and the corresponding class is 400- 500. 

Thus, the median class is 400 - 500.