If the mean deviation of $5$ observations about the mean $3$ is $1.2$,find the coefficient of mean deviation.

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

Let $S$ be the set of all values of $a_1$ for which the mean deviation about the mean of $100$ consecutive positive integers $a_1, a_2, a_3, \ldots, a_{100}$ is $25$. Then $S$ is

Mean deviation is least if it is taken about :-

If the mean of the data $p, 6, 6, 7, 8, 11, 15, 16$ is $3$ times $p$,then the mean deviation of the data from its mean is

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: