Standard deviation only for data that meets two conditions in Excel

Question

I'm attempting to determine the standard deviation for a set of data points that must satisfy two requirements. The precise example is: It is necessary to determine the yield standard deviation for the crop variety "Z1" in region "A." A list of a few thousand yields, together with their matching area and variety, is available. The results should be the standard deviation for the three values (1500, 1800, and 1600) in the table below that satisfy this requirement. All other yields should be disregarded.

Region  Variety Yield
A   Z1  1500
B   Z1  2100
B   X2  1900
A   X1  1700
C   Z2  2000
C   X1  1500
A   Z1  1800
B   Z2  2500
C   X1  1700
A   Z1  1600

I tried using this formula, but it does not work (also not as an array formula) and only returns "FALSE"

=IF(AND(Region="A",Variety="Z1"),STDEV.S(Yield))

Can someone please help me with this?

Answer 1

I would say:

=STDEV.S(IF((A2:A11="A")*(B2:B11="Z1"),C2:C11,""))

Array entered.