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Does anyone know when to use 'sample' or 'population' standard deviation and variance??
http://www.andrews.edu/~calkins/math/webtexts/stat05.htm
it looks like for 'sample' you divide by 'n-1' but for population you divide by 'n' and i'm not sure what the difference is and when to use which one...
i've seen both formulas in the DAT qr review sections of the books i've been using so now i'm confused.. 🙁 i always used the standard deviation formula with just 'n' used to divide the mess on top (square of the difference between values and mean)..
help!
http://www.andrews.edu/~calkins/math/webtexts/stat05.htm
it looks like for 'sample' you divide by 'n-1' but for population you divide by 'n' and i'm not sure what the difference is and when to use which one...
i've seen both formulas in the DAT qr review sections of the books i've been using so now i'm confused.. 🙁 i always used the standard deviation formula with just 'n' used to divide the mess on top (square of the difference between values and mean)..
help!
