Moving Average Access 07

[Gaetan M]

Suppose I have a query from which I make a table
In this table I have 3 fields
#1 a date (shipdt)
#2 the items to be averaged (sumofBOL)
#3 the warehouse (whouse)

So I want to do simple average for each week. How do I do this? Let's
imaging my week start on the 15th of August until the 19th and again
on the 22nd until the 26th, etc.
Also if I want to do a 3 week moving average how would I proceed.

Any help is appreciated.

Thanks