Question

Mean deviation of $39,40,40,41,41,42,42,43,43,44,44,45$ from their median is?

• A. $15$
• B. $1.5$
• C. $42$
• D. $35$

Answer 1

The correct option is B $1.5$

Arranged data is

$39,40,40,41,41,42,42,43,43,44,44,45$

Since $N=12=$even

Median$={\frac{\left(N/2\right)+\left[\right(N/2)+1]}{2}}^{th}$ term

Median$=\frac{42+42}{2}=42=M$ (Let)

Now, Mean deviation $=\frac{\sum |x_i-M|}{N}$

$=\frac{3+2+2+1+1+1+0+0+1+1+2+2+3}{12}=1.5$