Calculate weighted averages using high, medium, low

On another thread I found a solution to creating a weighted average given a pair of columns of numbers but I have column B consisting of values given as High, Medium and Low and the weighted column C of 1, 2 or 3.

How can I use the formula below to accomplish this, or is this maybe not the right way to created a weighted average?

=SUMPRODUCT(B2:B11,C2:C11)