You knew something like this had to be on the web!!

>>Hi All.
>>
>>I'm in a bit of a problem here. I need to compute the standard deviation on an array of values. I know it's easy to do it on table data: CALCULATE STD(numfield). But what is the actual textbook formula? Anyone got a mathematics textbook handy or a darn good memory?
>
>See http://www.hoxie.org/math/stat/stats.htm about half down the page.