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Subject: Re: [office-comment] ODFF: list of suggestions
Hello everyone, Eike Rathke wrote: > Hi David, > > [...] >> STDEVA >> "Estimates the standard deviation" - no, it calculates the >> standard deviation. The standard deviation *is* an estimate (of >> spread). >> > > Done for draft11. > This is slightly more complex: Lets say there is an infinite population and a finite sample from this infinite population. Suppose now that we *calculate* the standard deviations for the sample and somehow do it for the population, too. sd(sample) = sqr( ... / (n-1) ) sd(population) = sqr( ... / n ) [Notice the difference between the 2!] More often than not, we cannot calculate the population sd, so we need to *estimate* it. The best estimator of the population sd is actually the sample sd. So: sd(population) ~ sd(sample) [This is the reason why sd(sample) is with (n-1), to get a value more close to sd(population).] Therefore, we calculate the sd for a *sample*, but we usually wish to *estimate* the sd of the *population*. Sincerely, Leonard
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