STDEVX.P Returns the standard deviation of the entire population.
Syntax
STDEVX.P(table, expression)
Parameters
table – Any DAX expression that returns a single scalar value, where the expression is to be evaluated multiple times (for each row/context).
expression – Any DAX expression that returns a single scalar value, where the expression is to be evaluated multiple times (for each row/context).
Return Value
A number that represents the standard deviation of the entire population.
Reference Data
https://docs.microsoft.com/en-us/dax/dax-function-reference