Calculate mean deviation about mean from the following data:
`x_i :` 3,9,17,23,27,`f_i :`8,10,12,9,5

Explanation

`N=sum f_i=44`

`sum f_ix_i=660`

`sum f_i abs(x_i-15)=312`

`Mean= bar x=frac{1}{N}(sum f_ix_i)=frac{660}{44}=15`

`Mean deviation=M.D=frac{1}{N}(sum f_i abs(x_i-15))`

`=frac{312}{44}=7.09`