Questions tagged [stdevp]

STDEVP is used when the group of numbers being evaluated is complete - it's the entire population of values. In this case, the 1 is NOT subtracted and the denominator for dividing the sum of squared deviations is simply N itself, the number of observations (a count of items in the data set).

Technically, this is referred to as biased. Remembering that the P in STDEVP stands for population may be helpful. Since the data set is not a mere sample, but constituted of ALL the actual values, this standard deviation function can return a more precise result.

https://msdn.microsoft.com/en-us/library/ms176080.aspx