friends.
I’m new in DAX and stackoverflow, sorry
Please help to calculate stdev.p/stdevx.p for each month (month number).
For example: i have 5 years observations for each month and i need to calculate StatDev for only January’s (for all 5 Januarys), then for February’s (for all 5 Februarys), then for March’s and so on.

I wrote a measure

colOrdersMonth = MONTH(OrdersStatistics[Period]) ---calculated column
OrdersStatistics[NOMENCLATURA]) -----my SKU (sold goods)

mStdDev_Example = mStdDev_Example = CALCULATE(STDEVX.P(OrdersStatistics,OrdersStatistics[Sold]),ALLEXCEPT(Dates,Dates[Month]))

but i got blank values (even if i know that there were sales in those months)
StDev

Also i want to get the sum of all StDevs in total not the StDev for total =)