PERCENT AND PERCENTILE - AN EXAMPLE

Suppose 300 people take a test of 50 items.

If one of them got 40 of the items correct, then the percentage that he got correct is 80. He got 80 percent of the items correct.

But we don't know what percentile he is in until we see what scores the other 299 people got.

Suppose that 297 of those got only 60% (or fewer) of the items correct and other 2 got 90%. Then the person who got 80% did better than all other 297 people. He did better than 99% of the whole group of 300, so he is in the 99th percentile

Other Example:
A PM wants to fix weighting criteria that all vendors who are above of 70^th percentile will be called for bidding.
And following set of observation documented 

In below set of observation - what is rating %age above 70^th percentile and how many vendors could qualified?

Rating in %age	20	25	30	35	40	45	50	55	60	65	70	75	80	85	90	100
No. of Vendors obtained above rating	0	2			2		3		3	4	3		4	2	7	0
Cumulative	0	2	2	2	4	4	7	7	10	14	17	17	21	23	30	30

Solution

Rating in %age	20	25	30	35	40	45	50	55	60	65	70	75	80	85	90	100
Vendors obtained above rating	0	2			2		3		3	4	3		4	2	7	0
Cumulative	0	2	2	2	4	4	7	7	10	14	17	17	21	23	30	30
above nth Percentile = 100*cumulative/total number	0.0	6.7	6.7	6.7	13.3	13.3	23.3	23.3	33.3	46.7	56.7	56.7	70.0	76.7	100.0	100.0
no of vendors qualified	30	28	28	28	26	26	23	23	20	16	13	13	9	7	0	0