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

Find the mean deviation about the median of the following distribution:
$ \begin{array}{|l|l|l|l|l|l|} \hline \text{Marks obtained} & 10 & 11 & 12 & 14 & 15 \\ \hline \text{Number of students} & 2 & 3 & 8 & 3 & 4 \\ \hline \end{array} $

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 median of the numbers $3x, 6x, 9x, \ldots, 81x$ is $91$. Then $|x| = $

Find the mean deviation of the numbers $3, 4, 5, 6, 7$.