Calculate interquartile range, quartile deviation and the coefficient of quartile deviation from the following data:

Explanation

`Q_(1)`=Size of `((N+1)/(4))th" item"`
=Size of `((127+1)/(4))th "item "`
=Size of 32th item=40
`Q_(3)` =Size of `3((N+1)/(4))th " item" `
=Size of `3((127+1)/(4))th " item"`
=Size of 96th item=50
Interquartile Range`=Q_(3)-Q_(1)=50-40=10`
Quartile Deviation (QD)`=(Q_(3)-Q_(1))/(2)=(50-40)/(2)=(10)/(2)=5`
Coefficient of QD`=(Q_(3)-Q_(1))/(Q_(3)+Q_(1))=(50-40)/(50+40)=(10)/(90)=0.11`