Question

The coefficient of mean deviation from median of observations 40, 62, 54, 90, 68, 76 is

• A. 2.16
• B. 1.2
• C. 5
• D. none of these

Answer 1

The correct option is B 1.2

Arranging the given data in ascending order
40,54,62,68,76,90
Here, $n=6\left(even\right)$
$M=\frac{\text{value of}{3}^{rd}\text{observation}+\text{value of}{4}^{th}\text{observation}}{2}$
Median $M=\frac{62+68}{2}=65$
Mean deviation about median $M.D=\frac{|40-65|+|54-65|+|62-65|+|68-65|+|76-65|+|90-65|}{65}$
$=\frac{25+11+3+3+11+25}{65}=1.2$