Ron Rosenfeld wrote...
....
I do not believe that either COUNTIF or array functions can accept
non-contiguous ranges.

If you get tricky enough, you can come close.

=SUMPRODUCT(COUNTIF(OFFSET(N13,0,{0,10,14,20}),wha tever))

But I don't think this is what the OP is after. The OP would be vastly
better off using a database rather than a spreadsheet to calculate
conditional averages over several stores.