Find the mean deviation about the median for the following data:

Marks	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$
No of Girls	$6$	$8$	$14$	$16$	$4$	$2$

(N/A) To find the mean deviation about the median,we first calculate the median.

Marks	$f_{i}$	$C_{f}$	$x_{i}$	$|x_{i}-M|$	$f_{i}|x_{i}-M|$
$0-10$	$6$	$6$	$5$	$22.86$	$137.16$
$10-20$	$8$	$14$	$15$	$12.86$	$102.88$
$20-30$	$14$	$28$	$25$	$2.86$	$40.04$
$30-40$	$16$	$44$	$35$	$7.14$	$114.24$
$40-50$	$4$	$48$	$45$	$17.14$	$68.56$
$50-60$	$2$	$50$	$55$	$27.14$	$54.28$
Total	$N=50$	-	-	-	$517.16$

Here,$N=50$,so $\frac{N}{2} = 25$.
The cumulative frequency just greater than $25$ is $28$,so the median class is $20-30$.
Median $M = l + \frac{\frac{N}{2} - C_{f-1}}{f_{m}} \times h = 20 + \frac{25 - 14}{14} \times 10 = 20 + \frac{110}{14} = 20 + 7.86 = 27.86$.
Mean deviation about median $= \frac{\sum f_{i}|x_{i}-M|}{N} = \frac{517.16}{50} = 10.3432 \approx 10.34$.