Assuming the values to be averaged are running in C1 down

Put in D1:
=AVERAGE(OFFSET(C$1,ROWS($1:1)*15-15,,15))
Copy D1 down as far as required

D1 returns the average of C1:C15
D2 returns the average of C16:C30, and so on, as desired
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
---
"Bec" wrote:
Hi have a spreadsheet which has lines for every minute of the day

20/8/07 1900
20/8/07 1901 etc etc for a number of weeks.

How do I easily find the average of each 15 minute period without having to
copy and paste an average formula every 15 lines? and so it's in one table
(ie no gaps)

TIA
Bec