I need to be able to sum numbers in several columns and then calculate the
average of each of these summed columns. But I Only want to sum the numbers
where a 1 exists against that row of data. I have columns of dates and then
the time differences between the various dates in days. The dates signify
dates in a process. I need to calculated the averages of the various time
differences, but only where the whole process is complete. So I have a column
at the end with a "1" in it when that row has all data entered. Example of
what I have is (time diff is guessed here):

Col 1 Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 ..... col 8
1/3/06 2/3/06 1 12/4/06 40 16/4/06 4 1
2/4/06 5/4/06 3 29/4/06 24 5/5/06 6 1
5/6/06 8/6/06 3
0
3/7/06 5/7/06 2 16/7/06 11 20/7/06 4 1
20/7/06 24/7/06 4 29/7/06 5 0


I only what the averages for columns 3, 5 & 7, when there is "1" in Column 8

If there is not a simple way using formulae, can I just sum and then calc
the average by filtering on column 8 - I can't seem to do this either


Russell