Question

Find the sum of the lower limit of the modal class and upper limit of the median class for the following distribution. 

Class:	50 – 55	55 – 60	60 – 65	65 – 70	70 – 75	75 – 80
Frequency:	10	15	8	13	9	5

Answer 1

The class interval with the highest frequency is known as the modal class. According to the table, the highest frequency, which corresponds to classes 55 – 60, is 15.

Nodal class = 55 – 60

Lower limit of modal class = 55

Class	50 – 55	55 – 60	60 – 65	65 – 70	70 – 75	75 – 80
Frequency (f)	10	15	8	13	9	5
Cumulative Frequency (CF)	10	25	33	46	55	60

N = 60

Compute: `N/2 = 60/2 = 30`

Median class = 60 – 65

Upper limit of median class = 65

The required sum is:

Lower limit of modal class + Upper limit of median class

= 55 + 65 = 120