4. Calculate Decile deviation, Coefficient of D.D., Interdecile range from the following data
`4,14,12,16,6,3,1,2,3`

Solution:
Decile deviation :
Arranging Observations in the ascending order, We get :
`1,2,3,3,4,6,12,14,16`

Here, `n=9`

`D_1 = ((n+1)/10)^(th)` value of the observation

`=(10/10)^(th)` value of the observation

`=1^(st)` value of the observation

`=1`

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`D_9 = ((9(n+1))/10)^(th)` value of the observation

`=((9*10)/10)^(th)` value of the observation

`=9^(th)` value of the observation

`=16`

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InterDecile range `=D_9 - D_1=16-1=15`

Decile deviation `=(D_9 - D_1)/2=(16-1)/2=15/2=7.5` (Semi-InterDecile range)

Coefficient of Decile deviation `=(D_9 - D_1)/(D_9 + D_1)=(16-1)/(16+1)=15/17=0.8824`

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