We have n = 274
So, n/2 = 274/2 = 137
The cumulative Frequency just greater than n/2 is 152 then the median class is 21 – 28 such that
the lower limit (l) = 21
cumulative frequency of the class preceding 21 – 28 (cf) = 80
frequency of the median class 21-28 = 72,
class size (h) = 7
Using the formula,
Now, we have to find the mode
Here, the maximum class frequency is 72, and the class corresponding to this frequency is 21 – 28.
So, the modal class is 21 – 28.
Now, modal class = 21 – 28, lower limit (l) of modal class = 21, class size(h) = 7
frequency (f1) of the modal class = 72
frequency (f0) of class preceding the modal class = 36
frequency (f2) of class succeeding the modal class = 51
Now, let us substitute these values in the formula