The mean deviation from the mean of the discrete data $1, 3, 4, 7, 11, 18, 29, 47, 78$ 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

If $m$ and $M$ denote the mean deviations about the mean and about the median respectively of the data $20, 5, 15, 2, 7, 3, 11$,then the mean deviation about the mean of $m$ and $M$ is

The mean and variance of $10$ observations are $9$ and $34.2$,respectively. If $8$ of these observations are $2, 3, 5, 10, 11, 13, 15, 21$,then the mean deviation about the median of all the $10$ observations is

If $10$ is the mean of the data $2, 3, 5, 18, 17, 15, 13, x, 9, 7$,then the mean deviation of this data about its mean is

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

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