Question

In a class test, 50 students obtained marks as follows:

Marks obtained	0 – 20	20 – 40	40 – 60	60 – 80	80 – 100
Number of students	4	6	25	10	5

Find the modal class and the median class.

Answer 1

Here the maximum class frequency is 25, and the class corresponding to this frequency is 40-60.
So, the modal class is 40-60.
Now, to find the median class let us put the data in the table given below:

Marks Obtained	Number of students `(f_i)`	Cumulative frequency (cf)
0 – 20	4	4
20 – 40	6	10
40 – 60	25	35
60 – 80	10	45
80 – 100	5	50
Total	`N=Σf_i=50`

Now, 𝑁=50 ⟹`N/2=25.`
The cumulative frequency just greater than 25 is 35, and the corresponding class is 40 – 60.
Thus, the median class is 40 – 60.