Question

Following are the marks obtained by $9$ students in a mathematics te st: $50, 69, 20, 33, 53, 39, 40, 65, 59$ Mean deviation from the median is

• A. $9$
• B. $10.5$
• C. $12.67$
• D. $14.76$

Answer 1

Answer: (C)

$12.67$

Answer 2

Arranging the data in ascending order, we have $20, 33,39,40, 50, 53, 59,65,69$. Median $= \left(\frac{9+1}{2}\right)^{th}$ item $= 5^{th}$ item $= 50$ $\therefore$ Mean deviation from median $=\frac{\displaystyle\sum_{i=1}^{9}\left|x_{i}-50\right|}{9}$ $=\frac{1}{9}\left(30 + 17 + 11 + 10 + 0 + 3 + 9 + 15 + 19\right)$ $=\frac{114}{9}=12.67$.