For the nearest rank computation, you could use the following: $arr = array(12,89,65,23,90,99,9,15,56,67,3,52,78,12,10,88,77,77,77,77,77,77,77); sort($arr); $score_representing_95th_percentile = $arr[round((95/100) * count($arr) - .5)]; echo $score_representing_95th_percentile; // 90
That said, there are many ways to calculate percentile (I tend to think in Z-scores, myself), and nearest rank has its issues, depending on your needs: http://en.wikipedia.org/wiki/Percentile <http://en.wikipedia.org/wiki/Percentile>Hopefully the example and the link give you enough to get what you need working. Adam On Sat, Jan 29, 2011 at 11:15 AM, Paul Halliday <paul.halli...@gmail.com>wrote: > What is the quickest way to do this? Will stats_stat_percentile work? > If so, does anyone have examples of its operation? > > Keep in mind that my math is terrible. Use small words :) > > Thanks. > > -- > Paul Halliday > http://www.pintumbler.org > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > -- Nephtali: A simple, flexible, fast, and security-focused PHP framework http://nephtaliproject.com
