Great!
Replace the formula by =IF(F50,AVERAGE(F3:F5),"")
The item after the last comma is double quotes in a row.
This say: IF the value is F5 is greater than 0, then do the calculation,
else display nothing.

My old math teacher- an Irishman - was fond of saying "There are more ways
of killing a pig than stuffing it with butter", so here is another formula
to try
=IF(COUNT(F3:F5)<3,"",AVERAGE(F3:F5))

How do you like retirement? This is my first month!

best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Retiredff" wrote in message
nk.net...
OK. Very understandable.

Using the MPG Three Tank AVG column (F) as an example:

I started with =AVERAGE(F3:F5). I dragged it down to select the column.
The cell numbers increase by one with each fill-up, giving me my running
three-tank average.

If I want to find the High Average from all the averages in the three-tank
column (G), I have set up another column (K) (High Average Three Tank),
and tried to use this: =Max(G3:G25). My test sheet only has entries cell
25. It will give me the correct single High Average that is listed in
those cells. However, if I try to add more cells in column G to that
formula, in order for the High Average to update as I buy more gas, it
gives me #DIV/0! as the answer. It only works as long as the range of
cells already have numbers in them.

I apologize if this is still not clear, and is not the information you
asked for. When I read my answer to you, it makes sense. I mat just be
having a hard time expressing my answer in a way that others will
understand. My first thought was that you wanted the entire setup, but
that did not make sense to me, since the rest of it is working correctly.

Larry


Bernard Liengme wrote:
It would help if you told us how you had set out your data and what
formulas you are using.


"Retiredff" wrote in message
ink.net...
I am setting up a spreadsheet to track short and long-term fuel
economy. Single tank MPG was no problem. I have succeeded in getting
it to work so that it will give me a running average for three and
fifteen tank fills. I want to be able to track the minimum and maximum
MPG in each of the
three categories (single, three, and 15 tank). I can get it to work
as long as I have entries in those categories. I can't figure out
how to get it to check (compare?) as I add additional fill-ups to my
list. For instance, if I select the entire one-tank column, and use that
range in my formula, I wind up with #DIV/0! as the answer, even
though there are averages listed. If I only select the columns that
have an entry, then I get the correct figure.

I hope this is clear enough so someone will understand what I am
trying to do.

Many thanks.

Larry