• mdv 9731 (1/28/2011)


    I do not agree that the answer is right.

    Think it is supposed to be 0.

    the standard deviation s (sigma) is the square root of the average value of (X - ยต)2.

    Which means s = sqrt(((1-1)^2)/1) = 0

    Or in other words std. deviation equals sqrt of (population-avarage) sq / number of population values

    Please correct me if im wrong on the formula it has been a while since i used my statistics ๐Ÿ˜€

    Even if your statistics say it is 0, SQL Server returns NULL, so the answer is still correct.

    You can verify it by running the query in SQL Server Management Studio.

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