If the mean of the following frequency distribuition is 65.6 , find the missing frequencies `f_1 and f_2`

Explanation

We have
`5+8+f_1+20+f_2+2=50 rArr f_2=(15-f_1)`
Now , we may prepare the table given below

`therefore " mean "= (Sigma(f_ixxx_i))/(Sigmaf_i)=((3760-40f_1))/(50)`
But , mean =65.6(given).
`therefore ((3760-40f_1))/(50)=65.6 rArr 3760-40f_1=3260`
`rArr 40f_1=480 rArrf_1=12`
Thus, `f_1=12 and f_2=(15-12)=3`