Question

Find the mean deviation and variance of the following distribution. X 2 3 4 5 6 7 8 9 10
f 1 1 2 4 4 3 7 5 3

Answer 1

According to question

X = 2  3  4  5  6  7  8  9  10
f =   1  1  2  4  4  3  7  5   3

Mean Deviation can be calculated

Mean Deviation =  1 + 1 + 2 + 4 + 4 + 3 + 7 + 5 +3 / 9
                           = 30 / 9
                           = 10 / 3
Variance =   1 + 1 + 4 + 16 + 16 + 9 + 49 + 25 + 9 / 9
              = 130 /9