Question

Convert the following 'more than' cumulative frequency distribution into a 'less than' cumulative frequency distribution

Class-Interval (More than)	10	20	30	40	50	60	70	80
Frequency	124	119	107	84	55	31	12	2

Answer 1

The 'more than' cumulative frequency distribution can be presented in the form of a 'simple frequency distribution' as follows.

Class-Interval	Frequency
10 - 20 20 - 30 30 - 40 40 - 50 50 - 60 60 - 70 70 - 80 80 - 90	124 − 119 = 5 119 − 107 = 12 107 − 84 = 23 84 − 55 = 29 55 − 31 = 24 31 − 12 = 19 12 − 2 = 10 2

From the above distribution, we can make the 'less than' cumulative frequency distribution as follows.

Class-Interval	Frequency
Less then 20 Less then 30 Less then 40 Less then 50 Less then 60 Less then 70 Less then 80 Less then 90	5 5 + 12 = 17 17 + 23 = 40 40 +29 = 69 69 + 24 = 93 93 + 19 = 112 112 + 10 = 122 122 + 2 = 124