The mean deviation about the mean for the following data is:

$x_i$	$2$	$4$	$5$	$7$	$9$
$f_i$	$2$	$4$	$10$	$8$	$6$

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

Class	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$
Freq	$6$	$7$	$15$	$16$	$4$	$2$

If the mean deviation about the median for the numbers $3, 5, 7, 2k, 12, 16, 21, 24$ arranged in ascending order is $6$,then the median is:

If $a_0, a_1, \ldots, a_{11}$ are in an arithmetic progression with common difference $d$,then their mean deviation from their arithmetic mean is

The mean deviation about the mean for the following data is

Class Interval	$0-4$	$4-8$	$8-12$	$12-16$
Frequency	$4$	$3$	$2$	$1$

Let $\bar{X}$ and $M.D.$ be the mean and the mean deviation about $\bar{X}$ of $n$ observations $x_i,$ $i = 1, 2, \dots, n.$ If each of the observations is increased by $5,$ then the new mean and the mean deviation about the new mean,respectively,are