The mean deviation of the numbers $3, 4, 5, 6, 7$ is

Find the mean deviation about the median for the data.

${x_i}$	$5$	$7$	$9$	$10$	$12$	$15$
${f_i}$	$8$	$6$	$2$	$2$	$2$	$6$

If $10$ is the mean deviation of $n$ observations $x_1, x_2, x_3, \ldots, x_n$,then the mean deviation of the observations $\frac{2x_1+5}{3}, \frac{2x_2+5}{3}, \frac{2x_3+5}{3}, \ldots, \frac{2x_n+5}{3}$ is

If the mean deviation about the median of the numbers $k, 2k, 3k, \dots, 1000k$ is $500$, then $k^{2}$ is equal to :

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

If the mean deviation from the mean of the observations $\{1+K \alpha\}$,where $K=0, 1, 2, \ldots, 100$ and $\alpha > 0$ is $255$,then $\alpha =$