We have n = 80
So, n/2 = 80/2 = 40
The cumulative Frequency just greater than n/2 is 56 then the median class is 40 – 50 such that
the lower limit (l) = 40
cumulative frequency of the class preceding 40 – 50 (cf) = 37
the frequency of the median class 40 – 50 =19,
class size (h) = 10
Using the formula,
= 40 + 1.58
= 41.58