Help with STDEV IF formula

[El Ruck]

Hey y'all,

I'm trying to get the STDEV of AF2:AF2401 IF T2:T2401 is > 100 AND T2:T2401 is < 201, and IF W2:W2041=BV1.

This formula works, confirmed with CTRL SHFT ENTR:
=STDEV(IF($T$2:$T$2041<201, IF($W$2:$W$2041=$BV$1, $AF$2:$AF$2041)))

And this one works:
=STDEV(IF($T$2:$T$2041>100, IF($W$2:$W$2041=$BV$1, $AF$2:$AF$2041)))

I just can't figure out how to combine them, to effectively search T2:T2401 for values that are >100 and <201. I don't think you can use AND for arrays, so I've tried multiple IFs:
=STDEV(IF($T$2:$T$2041>100, IF($T2:$T$2401<201, IF($W$2:$W$2041=$BV$1,$AF$2:$AF$2041)))) CTRL SHFT ENTR
but I get an N/A error.

Halp! I've been stuck here for a day!

 

[BiocideJ]

Although you cannot use the AND function like you stated, the multiplication operator works often as a good stand-in.

i.e.
TRUE*TRUE = 1*1 = 1 = TRUE
FALSE*TRUE = 0*1 = 0 = FALSE
TRUE*FALSE = 1*0 = 0 = FALSE
FALSE*FALSE = 0*0 = 0 = FALSE

It's not entirely intuitive, but I believe this formula does what you are asking...
=STDEV(IF(($T$2:$T$2041>100)*($T$2:$T$2041<201), IF($W$2:$W$2041=$BV$1, $AF$2:$AF$2041)))

 

[El Ruck]

Genius. Solved. A million thanks.

 

[BiocideJ]

Genius indeed, just not my genius. I once had the same question myself a while back.