4) For the following Histogram:
a) Deduce the grouped frequency distribution.
b) Calculate the sample mean and variance.
c) Find the value of the median.

frequency 6... 8.... 10... 1... 1....///// 5.5-20.5 20.5-35.5 35.5-50.5 50.5-65.5 65.5-80.5 Class Boundaries

the answers which i got
mean 30.38
variance 418.6
median 48.625​