I'm a little stumped here as to why this formula works...
=AVERAGEIF(Table1[Day],O39,Table1[D])
...and this one returns a #DIV/0! error.
=AVERAGEIF(Table1[Day],OR(O39,O40,O41,O42,O43),Table1[D])
The only difference between them is that in the first, I need the average associated with one...