For all those wondering how the Standard Deviation in Microsoft Excel is used :

The excel function STDEV works correctly as explained in the post by McGimpsy:

1/(1-n).sum( x;i - x;mean) ^2

The confusion however is that the Microsoft Help for the function claims
STDEV works as follows :

1/(1-n).sum( x;i^2 - x;mean^2)

Wich is a bunch of ballocks as the function works just as it should, and
just like statisticians would use it.

Regards,
Robin


--
Robin Vervoorn
"You can't teach a new mouse old clicks.."



"Ganapati Hegde" wrote:

Hi Microsoft Office,

The formula for Standard Deviation provided in Excel ( =STDEV(range) )gives
a different answer when compared with the answer got by manually calculating
the Standard Deviation formula provided in the Statistics text books.

E.g.: Numbers - 5, 6, 8 & 9. When calculated using Microsoft Excel =STDEV
(....) we get an answer 1.82574185835055

But when calculated using the Text book methods of calculating of the Std.
Dev. formula, we get 1.58113883008419

Please can you advise why there is a difference in the answers?

Please can you make appropriate changes in the future Microsoft Office
releases giving the breakup of the formulas used? May be in the HELP option.
Because there are millions of excel users who are completely dependent
(unaware) on the formule in excel.

Many thanks,

Ganapati Hegde
Mumbai, INDIA.
+91 98195 58330


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