Golf league form

don't delete it just use the formula to take the last 3.  For example if the whole range is F1:AG1 and all the 'future' weeks are empty (as in no data, no number, no formula, no text) then an easy way is to use:

TAKE(F1:.AG1,,-3)

NOTE there is a period after the colon and before AG, that is a shortcut for the funtion TRIMRANGE which will remove empty cells (form beginning, end or both depending on how you set it up).

also note there are 2 commas because you want the columns (not rows)

so this formula looks at the range F1:AG1 and 'trims' it down to where there is data then take the first 3 columns from the END (hence the negative 3)

now you can take the average like: =AVERAGE(TAKE(F1:.AG1,,-3))

Hope that helps