I have recently figured out how to calculate the weighted average of, say, contact time on the telephone vs call quantity. Ie,

=SUMPRODUCT(C:C,H:H)/SUM(C:C)

^ This gives me the average contact time for a team of agents.

BUT! How do I get this calculation in a pivot table? The reason for doing so is so that I can have the average contact time split by work-week.