Question

C.I =5-10,10-15,15-20,20-25,25'30,35-40,40-45 ______frequency=5,6,15,10,5,4,3,2find the mean of this following data :-​

Answer 1

The mean can be counted by three methods i.e. shortcut, diret,step-deviation method.

i suggest you to use step- deviation .