Question

Draw a more-than type cumulative frequency curve for the following data on time required to do a certain job.

Time required (in hours)	above 50	above 70	above 90	above 110	above 130	above 50	above 50
Number of workmen	100	98	90	60	35	21	2

Answer 1

To draw the more-than type cumulative frequency curve, we prepare the following table.

Time required (in hrs)	More- than cumulative frequency (Fi )	Lower boundary (li )
50-70	100	50
70-90	98	70
90-110	90	90
110-130	60	110
130-150	35	130
150-170	21	150
170-190	2	170

The more-than cumulative frequency curve is shown below.