The class marks of a distribution are 6,10,14,18,22,26,30 then the class size is
the class marks of a frequncy distribution are 6,10,14,18,22,26,30.Find its class size
If the class Mark in a frequency distribution are 19.5,26.5,33.5,40.5,47.5,54.5,61.5, then the class size of distribution is