functions with nonadjacent cells

[PCdummy]

I want to take several averages of nonadjacent cells but all I get is the
average of each column. I know how to select nonadjacent cells but cant get
the average function to work. I have 4 columns and 30 rows and want to take a
"rolling" average of 24 cells at a time. How can I do this?

 

[JE McGimpsey]

How does your data roll? Where does the non-adjacent part come in?

If you just want a rolling average of the last 24 entries in a column of
contiguous data, use something like:

=AVERAGE(OFFSET(A1,COUNTA(A:A)-24,0,24,1))