Question

The mean deviation of the data $3,10,10,4,7,10,5$ from the mean is

• A. 2
• B. $2.57$
• C. 3
• D. $3.75$

Answer 1

Answer: (B)

We have, $3,10,10,4,7,10,5$
Mean $(\bar{x})=\frac{3+10+10+4+7+10+5}{7}$
$=\frac{49}{7}=7$
Mean deviation $=\frac{1}{n}\sum _{i=1}^7\left|x_i-\bar{x}\right|$
$=\frac{\left[|3-7|+|10-7|+|10-7|+|4-7|+|7-7|+|10-7|+|5-7|\right]}{7}$
$=\frac{4+3+3+3+0+3+2}{7}=\frac{18}{7}=2.57$