Thanks for the prompt response, but I am looking for this running total
to be in a single cell for all 12 months of the year. This cell is next
to a cell that to doing a SUM of all widgets YTD. So say in Jan you
have 3 (D5)widgets at 3:25 (E5), and in Feb you have 10 (D6) widgets at
2:15 (E6). If you average you get 2:50. However the correct answer is
2:31. D7 equals the total of 13 widgets. (see formula below).
The key to this is understanding that these entries are in the same
location on individual monthly Sheets Jan-Dec and I am trying to
capture it on an EOY sheet that is identical to the monthly sheets.

=((D5*E5)+(D6*E6))/D7 <==This works on a flat file