Question

The following table shows the distribution of the height of a group of factory workers.

Ht (cm)	$150-155$	$155-160$	$160-165$	$165-170$	$170-175$	$175-180$	$180-185$
No. of workers	$6$	$12$	$18$	$20$	$13$	$8$	$6$

Determine the Cumulative frequencies.

Answer 1

Find the Cumulative Frequencies

The cumulative frequency is the summation of the current and the previous frequencies.

The cumulative frequency table for the given distribution is as follows

Height in cm	No of workers f	Cumulative frequency
$150-155$	$6$	$6$
$155-160$	$12$	$6+12=18$
$160-165$	$18$	$18+18=36$
$165-170$	$20$	$36+20=56$
$170-175$	$13$	$56+13=69$
$175-180$	$8$	$69+8=77$
$180-185$	$6$	$77+6=83$
	$N=83$

The total frequency will always be equal to the last cumulative frequency $N=83$