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

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

Here, `n=9`

`P_10 = ((10(n+1))/100)^(th)` value of the observation

`=((10*10)/100)^(th)` value of the observation

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

`=1`

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`P_90 = ((90(n+1))/100)^(th)` value of the observation

`=((90*10)/100)^(th)` value of the observation

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

`=16`

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InterPercentile range `=P_90 - P_10=16-1=15`

Percentile deviation `=(P_90 - P_10)/2=(16-1)/2=15/2=7.5` (Semi-InterPercentile range)

Coefficient of Percentile deviation `=(P_90 - P_10)/(P_90 + P_10)=(16-1)/(16+1)=15/17=0.8824`

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