Weighted Avg

I am trying to calculate the weighted average on a product line. I have three products that make up one product line and those three products have different gross margin dollars and gross margin percentages. I need to weight the product line accordingly based on sales. I have attached an example worksheet of what I am trying to accomplish.

Thanks!

try this

=SUMPRODUCT(B4:B6,C4:C6)/SUM(B4:B6)