I couldn't reproduce a difference in behavior:

STDEVA STDEV
5 5
7 7
3 3
8 8
DNS 0
9 9
2 2
DNS 0
9 9
9 9
10 10
10 10
8 8

3.71587033 3.71587033



It appeared to treat DNS as zero as specified in the help

in the formula bar, highlight this much of your formula

IF(Status="ENROLLED",Marks)

and Hit F9 to evaluate it and see what array it is returning? Note that
IF(Status="ENROLLED",Marks) will return false for "NOT" and both AverageA
and STDEVA would treat that as zero, but I believe I already pointed that
out for AverageA.

--
regards,
Tom Ogilvy


"AnandaSim" wrote in message
ps.com...
Thanks Tom, I've got a new wrinkle:

Student Status Marks
Joe ENROLLED 20
George NOT 10
Dick ENROLLED DNS
Alan ENROLLED 10

=AVERAGEA(IF(Status="ENROLLED",Marks))

as an array formula works fine - it handles the "DNS" as a zero.

=STDEVA(IF(Status="ENROLLED",Marks))

fails. It does not count the DNS as a zero. It acts like STDEV.
If I replace the cell containing DNS with zero, then it calculates
differently.

Any wisdom appreciated.

Thanks