not sure if this can be done rolling averages
 

Assuming you are going to enter these by date going down the sheet, starting
in row 2, and assuming you have the date in col A and the # of custoemrs in
col B. Then, in cell C3 try

=AVERAGE(OFFSET(C2,-MIN(19,ROW(B2)-2),-1,MIN(20,ROW(B2)-1),1))


"Aaron H" wrote:

Hello everyone, thanks all in advance for any comments and help.

I have been asked to create a spread sheet for work that tracks the number
of customers that come into our buisness througout the 24hour day, recored
the number of customers and then create a rolling three week average. an
examble of this would be monday april 18th 10 people were in the store,
monday april 25 5 people came into the store and moday may 2nd 10 more people
came into the store so the average of this is 3..were my problem is I need a
way to automatically drop april 18th out of the equation when i put in the
data for may 9th? is there a way to automatically do this?
again thanks in advance
Aaron