The mean deviation about the mean for the data $4, 7, 8, 9, 10, 12, 13, 17$ is

Find the mean deviation about the median for the following data: $3, 9, 5, 3, 12, 10, 18, 4, 7, 19, 21$ (in $.27$)

The mean deviation of the following data about its mean is

$x_i$	$5, 15, 25, 35, 45$
$f_i$	$8, 48, 56, 32, 16$

The frequency distribution of the age of students in a class of $40$ students is given below.

Age	$15$	$16$	$17$	$18$	$19$	$20$
No. of students	$5$	$8$	$5$	$12$	$X$	$Y$

If the mean deviation about the median is $1.25$,then $4X + 5Y$ is equal to:

Calculate the mean deviation about the mean of the set of first $n$ natural numbers when $n$ is an odd number.

The mean deviation from the median of the data $16, 22, 3, 14, 5, 10, 8, 6, 11, 4$ is