Finding Average before all information gathered

[gocolonel77]

Attached is a more simplistic form of a more complex workbook.

Cell B6 finds the average for the above cells (B2:B5)

However Cells B4 and B5 are awaiting information from other cells.

I want to be able to know what my average is before all four cells (b4:b5) are complete.

Additional factoid is the version of excel i am using in this instance is 2000

Thanks in advance

Addendum

Ok a new issue still working with Excel 2000.

See attachment, but delete value in F3

Lets say F3 is still awaiting information to be entered.

I do not want the average in B6 to be calculated until all four weeks have been entered for the quarter.

Any suggestions?

Thanks