The percentile rank of a score is the percentage of scores in its frequency distribution table which are the same or lesser than it. By knowing the distribution of scores, PR (Percentile Rank) can easily be identified for any sources in the statistical distribution. Here is a simple percentile formula to find the percentile rank. The percentile class rank is calculated based on the total number of ranks, number of ranks below percentile and number of ranks above percentile.
Statistics Percentile ranks are useful when you want to quickly understand the comparison between a particular score and other scores in a distribution of scores.