Looking to calculate the standard deviation of all the values in column C where the corresponding values in column O equal to "yes".

Tried this

=STDEV((O3:O82="yes")*(C3:C82))

or

=STDEV((O3:O82="yes")*(C3:C82)+0)

or

=STDEV(IF((O3:O82="yes"),(C3:C82)))

using CSE

but all return the wrong answer...

What as I doing wrong?

Thanks a lot in advance.

J.