I have a workbook that contains 3 worksheets, one for each vendor site. I am
trying to average delivery time (column R) across all 3 sites based on which
performer handled the request (column H). Is this possible?

I am writing a formula that looks like this:

=AVERAGE(IF(Sheet1:Sheet3!$H$3:$H$1002="Performer1 ",Sheet1:Sheet3!$S$3:$S$1002))

However, this is not working. I also have tried this:

=AVERAGE(IF(Sheet1!$H$3:$H$1002,Sheet2!$H$3:$H$3:$ H$1002,Sheet3!$H$3:$H$1002="Peformer1",Sheet1!$R$3 :$R$1002,Sheet2!$R$3:$R$1002,Sheet3$R$3:$R$1002))

This is not working either. Is this something that can be done or should I
just do a statistical summary sheet and run the formulas from there?