Find the mean deviation about median for the following data:
Find the mean deviation about median for the following data:

Solution:-

Draw  the table of the given data and append other columns after calculations.

The class interval containing 

    \[{{N}^{th}}/2\]

or

    \[25\]

 item is

    \[20-30\]

So,

    \[20-30\]

is the median class.

Then,

Median = l + (((N/

    \[2\]

) – c)/f) × h

Where, l =

    \[20\]

, c =

    \[14\]

, f =

    \[14\]

, h =

    \[10\]

and n =

    \[50\]

Median =

    \[20+(((25-14))/14)\times 10\]

=

    \[20+7.85\]

=

    \[27.85\]

So

    \[\sum\limits_{i=1}^{6}{{{f}_{i}}\left| {{x}_{i}}-Med \right|=517.1}\]

And M.D.(M) =

    \[\frac{1}{N}\sum\limits_{i=1}^{6}{{{f}_{i}}\left| {{x}_{i}}-Med \right|}\]

=

    \[(1/50)\times 517.1\]

=

    \[10.34\]

Therefore, the mean deviationabout the median is

    \[10.34\]