=SUM(C9:S9*$C$3)/SUM($C$3:$L$3)按CTRL+SHIFT+ENTER,你的公式有错
=sumproduct(C9:S9*$C$3:$S$3)/SUM($C$3:$L$3)
=SUMPRODUCT(C9:S9*C3:S3)/SUM(C3:L3)