Take a look at the following explanation of SUMPRODUCT by Bob Phillips
http://xldynamic.com/source/xld.SUMPRODUCT.html

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Regards

Roger Govier


"Watercolor artist" wrote in
message ...
In "sumproduct(--(" what's the purpose of (--?

Howard

"bj" wrote:

try
=if(K1="no",sumproduct(--(I5:I30<"House"),F5:F30),Sum(F5:F30))

"Watercolor artist" wrote:

In column F, from F5..F30, I have a set of dollar amounts that I want
to sum.
However, if the value in cell K1="no" then I do not want to include in
the
sum any value in column F that has in the same row the value "House" in
column I.

Howard