I want to average only some of the values in a column, based on tests on
other cells in the same row.

For example:
Suppose I have numeric values in A1:A10 and alpha characters in columns
B1:B10 and C1:C10.
If the value in cell B1="ORD" and the value in cell C1="MIA" then use the
numeric value in cell A1 in the average. If these two conditions are not
TRUE then treat cell A1 as blank.
I want this same check to apply to each row.
So I want to average only the An cells that meet this condition.

Can anyone help me code this function?