j9:bm17 contains an array, and $BQ1 contains the number of a row in that array. I want to compute the sumproduct of that row with j24:BM27. My best guess so far was:
=SUMPRODUCT(INDEX($J$9:$BM17,$BQ1),$J27:$BM27)
but that produces an error message saying “wrong data type”. How can I do this?