Question

Find the mean deviation and coefficient of mean deviation of number of TV sets using the following frequency distribution of TV sets sold in last 16 months in a town:

No. of TV sets	10 - 30	30 - 50	50 - 70	70 - 90	90 - 110
No. of months	1	4	6	4	1

Answer 1

Mean:

x̄ = \(\frac{Σfx}{n}\)= \(\frac{960}{16}\) = 60 TV sets

Mean deviation of monthly sales of TV sets:

MD = \(\frac{Σf|x−\bar x|}{n}=\frac {240}{16}\) = 15 TV sets

Coefficient of Mean deviation of monthly sales of TV sets:

Coefficient of mean deviation = MDx¯=1560 = 0.25