Hmm... I though I'd understood how SUMPRODUCT works but clearly I haven't.
Basically what I want to do is just find the nth largest number in a range
where an adjacent range ="X". So if I have the following two columns (hope
the formatting sort of works):

A B
X 1
3
2
X 2
5
X 4

I thought I could somehow do this with
=LARGE(SUMPRODUCT(--(range1="X"),--(range2),n) But that just gives me the sum
of the values in range2 for which the value in range1 is "X" so obviously
SUMPRODUCT only returns a single number... I obviously don't get very far by
sticking LARGE inside the SUMPRODUCT, either... any ideas?