I have a spreadsheet that has about 3500 rows. I have one column that has a
formula subtracting certain times. On some of the results I get a negative
result because some of the times are missing.

Here is my formula:

=IF(Disposition="Home",L4-K4,"xx")

L4 is often left blank because they don't have the time.

I need to do an average of these times but the average will not work because
of some of the negative results. Is there a way around this?

Denise