Find the mean deviation about the mean for the data.

    \[38\]

,

    \[70\]

,

    \[48\]

,

    \[40\]

,

    \[42\]

,

    \[55\]

,

    \[63\]

,

    \[46\]

,

    \[54\]

,

    \[44\]

Find the mean deviation about the mean for the data.

    \[38\]

,

    \[70\]

,

    \[48\]

,

    \[40\]

,

    \[42\]

,

    \[55\]

,

    \[63\]

,

    \[46\]

,

    \[54\]

,

    \[44\]

Solution:-

To find mean deviation, first we have to find mean

    \[(\overline{x})\]

    \[\overline{x}=\frac{1}{10}\sum\limits_{i=1}^{10}{{{x}_{i}}}=\frac{500}{10}=50\]

Determine the respective values of the deviations from mean,

i.e.,

    \[{{x}_{i}}-\overline{x}\]

are,

    \[50-38=-12\]

,

    \[50-70=-20\]

,

    \[50-48=2\]

,

    \[50-40=10\]

,

    \[50-42=8\]

,

    \[50-55=-5\]

,

    \[50-63=-13\]

,

    \[50-46=4\]

,

    \[50-54=-4\]

,

    \[50-44=6\]

The deviations are

    \[-12,20,-2,-10,-8,5,13,-4,4,-6\]

Therefore, the absolute values of the deviations,

    \[12,20,2,10,8,5,13,4,4,6\]

    \[\sum\limits_{i=1}^{10}{\left| {{x}_{i}}-\overline{x} \right|}=84\]

We know that Mean deviation = sum of deviations/ number of observations

=

    \[84/10\]

=

    \[8.4\]

Hence, the mean deviation for the given data is

    \[8.4\]