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calculation of standard deviation is not as help document says
in the help manual of STDEV, it is said that the calculation uses the
"unbiased" formula, but in fact the actual calculation uses the biased one, i.e. sqrt( sum(xi-xavg)/N), instead of the intended: sqrt( sum(xi-xavg)/(N-1)). am i right? if so, please correct the help document, to avoid the confusion. ---------------- This post is a suggestion for Microsoft, and Microsoft responds to the suggestions with the most votes. To vote for this suggestion, click the "I Agree" button in the message pane. If you do not see the button, follow this link to open the suggestion in the Microsoft Web-based Newsreader and then click "I Agree" in the message pane. http://www.microsoft.com/office/comm...lic.excel.misc |
calculation of standard deviation is not as help document says
"samemistake" wrote in message
... in the help manual of STDEV, it is said that the calculation uses the "unbiased" formula, but in fact the actual calculation uses the biased one, i.e. sqrt( sum(xi-xavg)/N), instead of the intended: sqrt( sum(xi-xavg)/(N-1)). am i right? if so, please correct the help document, to avoid the confusion. No, You're wrong, I think. It looks to me as if STDEV uses N-1 and STDEVP uses N, which is what the help says. I'm using Excel 2003. What numbers have you used to convince yourself that it's wrong? Which version of Excel? -- David Biddulph |
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