You can indeed use TRANSPOSE, but the whole furmula must be validated as
Array furmula (Ctrl+Shift+Enter):
=SUMPRODUCT(TRANSPOSE(B1:D1),A1:A3)

HTH
--
AP

"issy" a écrit dans le message de news:
...
With the SumProduct formula, the arrays must have the same dimensions. So
how
can I use it when I want to sum the product of a horizontal row of data
and a
vertical column of data? I've tried messing around with the Transpose
function but I can't get it to work with SumProduct.