Given, Numbers of observations are given.

To Find: Calculate the Mean Deviation.

Formula Used: Mean Deviation =

Explanation: Here, Observations 34, 66, 30, 38, 44, 50, 40, 60, 42, 51 are Given.

Since, Median is the middle number of all the observation,

So, To Find the Median, Arrange the numbers in Ascending order, we get

30, 34, 38, 40, 42, 44, 50,51, 60, 66

Here the Number of observations are Even then the middle terms are 42 and 44

Therefore, The Median = = 43

Deviation |d| = |x-Median|

And, The number of observations is 10.

Now, The Mean Deviation is

Mean Deviation =

Hence, The Mean Deviation is 8.7