Question

Class 40 50 50 60 60 70 70 80 80 90 90 100 Frequency 10 25 28 p 10 15

Answer 1

First of all make classes of repeatations and it's frequency(let's denote f) as per the datum given:- 40---1(f) 50---2(f) 60--2(f) 70--2(f) 80--2(f) 90--2(f) 100-1(f) These 1,2,2,2,2,2&1 are the frequencies of datum 40,50,60,70,80,90&100 respectively If we add up 1,3,5,7,9,11 &12 will be the cumulative frequency upto that class.