anilsolipuram wrote...
Try this

=3DSUMPRODUCT(--(A1:A6<0),B1:B6,A1:A6)/(SUMPRODUCT(--(A1:A6<0)))

WRONG! Try reading the OP's follow-up. Column *B* contains the weights.

"A zero-weighted average would just be the following formula
sumproduct(A1:A6,B1:B6)/sum(B1=AD:B6)"

There's no need for a conditional expression in the numerator, only the
denominator.

=3DSUMPRODUCT(A1:A6,B1:B6)/SUMIF(A1:A6,"<0",B1:B6)

since the 0s in col A will effectively exclude the corresponding col B
values from the SUMPRODUCT result.