Append previous cell data

I'm inputing numbers into a cell and I'd like another cell to retain the previous number and append it to the "=average" formula.

For instance:
Cell 1 = 455
Cell 2 = =Average(Cell1)

Then:
Cell 1 = 575
Cell 2 = =Average(455, Cell 1)

And so on, and so on.

Thanks!

Put this in a Module:

Please Login or Register  to view this content.

I used cell A1 as cell1 and any other cell as cell2. Put this formula in cell2:
=runningAverage(A1)

Works great, thanks!