Question

The mean deviation of the numbers 3, 4, 5, 6, 7 is

• A. 0
• B. 1.2
• C. 5
• D. 25

Answer 1

Answer: (B)

1.2

Answer 2

A.M. = $\frac{3 + 4 + 5 + 6 + 7}{5} = 5$

∴ Mean deviation$= \frac{\Sigma|x_{i} - \bar{x}|}{n}$

$= \frac{|3 - 5| + |4 - 5| + |5 - 5| + |6 - 5| + |7 - 5|}{5}$

$= \frac{2 + 1 + 0 + 1 + 2}{5} = \frac{6}{5} = 1.2$