Excel AVERAGEIFS Limit

Somebody asked how to solve a problem with the =AVERAGEIFS function and non-contiguous ranges. The solution requires a combination that uses a group of =SUMIFS function divided by an equivalent group of =COUNTIFS functions.

The following illustration shows the problem. It has groups of quarters, and within the quarter groups rows hold products and columns hold weeks. Unfortunately, the =AVERAGEIFS function disallows non-continguous source ranges. It does support multiple criteria, which may be non-contiguous ranges provided they match the number of elements in the source range.