Find out first and third quartiles from the following distribution :

Explanation

`Q_(1)=N/4"th item"=40/4"th item"=10"th item"`
`A_(1)"class"=25-50`
`sumf_(1)=4, f_(Q1)=16,l_(1)=25, i =25`
`Q_(1)=l_(1)+(((N)/(4)-sum f_(1))/(f_(Q1)))i =25+((10-4)/(16))xx25`
`=25+((6xx25)/(16))=25+(150)/(16)=25+9.375`
`=34.375"marks"`
`Q_(3)=l_(1)+(((3N)/(4)-sumf_(1))/(f_(Q3)))i`
`Q_(3)=(3N)/(4)"th item"=(3xx40)/(4)"th item"=`
`Q_(3)"class" =50-75`
`sumf_(1)=20, f_(Q3)=12,l_(1)=50, i =25`
`Q_(3)=50+((30-20)/(12))xx25=52+(10xx25)/(12)=50+(250)/(12)`
`=50+20.83=70.83"marks"`