Multiple-column based lookups in Excel

Question

        A     B    C
    1 PROD1 TYPE1 VAL1
    2 PROD2 TYPE1 VAL2
    3 PROD1 TYPE2 VAL3
    4 PROD2 TYPE3 VAL2 

In an empty cell I want to get th

Answer 1

=SUMPRODUCT(($A$1:$A$4="PROD2")*($B$1:$B$4="TYPE3")*($C$1:$C$4))

This assumes that column C values are actually numbers and not text.