Consider the following frequency distribution:

Class	0 - 10	10 - 20	20 - 30	30 - 40	40 - 50	50 - 60
Frequency	3	9	15	30	18	5

The modal class is

For modal class,

Here, the maximum class frequency is 30.

The class corresponding to this frequency is the modal class. ⇒ modal class = 30 - 40

∴ modal class = 30 - 40