First, let us make a cumulative frequency distribution of less than type.

In this case,

Sum of all frequencies, n = 53

Now, we know the median class is whose cumulative frequency is greater than and nearest to .

As, a Cumulative frequency greater than and nearest to 26.5 is 29, the median class is 60 - 70.

Median

where l = lower limit of median class,

n = number of observations,

cf = cumulative frequency of class preceding the median class,

f = frequency of median class,

h = class size

In this case,

l = 60

n = 53

cf = 22

f = 7

h = 10

Putting values, we get,

Median