Just a little technical note,
You divide by "n" if your sample represent the entire set of values.
If your data is a sample (a subset of the population) then you need to divide by n-1. I think that VFP std dev. is the latter.


>>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.