4. Calculate Mean deviation, Coefficient of M.D. from the following data
`3,23,13,11,15,5,4,2`

Solution:
Mean deviation :
Mean `bar x=(sum x)/n`

`=(3+23+13+11+15+5+4+2)/8`

`=76/8`

`=9.5`

`x`	`|x - bar x| = |x - 9.5|`
3	6.5
23	13.5
13	3.5
11	1.5
15	5.5
5	4.5
4	5.5
2	7.5
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`76`	`48`

Mean deviation of Mean
`delta bar x = (sum |x - bar x|)/n`

`delta bar x = 48/8`

`delta bar x = 6`


Coefficient of Mean deviation `=(delta bar x)/(bar x)`

`=6/9.5`

`=0.6316`

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