how do I get excel to add,then average numbers with two decimals?

[wenz324]

ie I need to tally little athletics results. I need the average of the best
three scores.
These are times (minutes, seconds and hundredths of seconds) and I now
realise we probably should have been entering using colons throughout the
season. I'm trying to fix the problem without having to manually change the
results into times.

3.06.51
3.11.43
3.22.56
3.23.94
3.56.29

 

[Charles Williams]

If they all start with 3 minutes then you can convert them to times by Edit
Replace 3. with 3:
Then format them with a custom format hh:mm:ss.00 so you can see whats
happening

Then use this array formula (assumes best means smallest time)

=AVERAGE(SMALL($A$1:$A$4,{1,2,3}))

you need to enter this array formula using Control-Shift-Enter

Charles
__________________________________________________
Outlines for my Sessions at the Australia Excel Users Group
http://www.decisionmodels.com/OZEUC.htm

 

[joeu2004]

I need the average of the best three scores.
These are times (minutes, seconds and hundredths of seconds) and I now
realise we probably should have been entering using colons throughout the
season. I'm trying to fix the problem without having to manually change the
results into times.

You might consider converting the "times" first. The "manual" process might
not be as complicated as you think. If the times below are in A1:A5, put the
following formula into B1 and copy down through B5:

=--SUBSTITUTE(A1, ".", ":", 1)

Select and copy B1:B5, then paste-Special Value back to A1:A5, and format
A1:A5 as Custom "mm:ss.00". You can now remove B1:B5, which might show
#VALUE errors now anyway.

Now, you can average them in the normal manner. For example, for the
average of the best of 3, enter the following as an array formula
(ctrl+shift+Enter):

=AVERAGE(LARGE(data,ROW(A1:A3)))

Alternatively, the following regular (non-array) formula does the same thing:

=SUMPRODUCT(LARGE(data,ROW(A1:A3))) / 3

You will need to format the result as Custom "mm:ss.00".

HTH.


----- original posting -----

 

[Gary''s Student]

With data in A1, In B1 enter:
=TIME(0,LEFT(A1,1),MID(A1,3,2))+RIGHT(A1,2)/(24*600*600)
and format as Custom m:ss.00

 

[joeu2004]

Errata....

For example, for the average of the best of 3, enter the
following as an array formula (ctrl+shift+Enter):
=AVERAGE(LARGE(data,ROW(A1:A3)))
Alternatively, the following regular (non-array) formula does the same thing:
=SUMPRODUCT(LARGE(data,ROW(A1:A3))) / 3

I guess the best of 3 is SMALL(), not LARGE().

Also, "data" should be A1:A5. An artifact of cut-and-pasting from my
worksheet. Note that "ROW(A1:A3)" is simply a way of getting the numbers 1
through 3. It has nothing to do with the data in column A.

 

[T. Valko]

=AVERAGE(SMALL($A$1:$A$4,{1,2,3}))

you need to enter this array formula using Control-Shift-Enter

No need to array enter.

 

[Ron Rosenfeld]

ie I need to tally little athletics results. I need the average of the best
three scores.
These are times (minutes, seconds and hundredths of seconds) and I now
realise we probably should have been entering using colons throughout the
season. I'm trying to fix the problem without having to manually change the
results into times.

3.06.51
3.11.43
3.22.56
3.23.94
3.56.29

If you don't want to convert your data, you could use these **array-entered**
formulas:

Add all the results:

=SUM(--("0:"&SUBSTITUTE(A1:A5,".",":",1)))

Average the best three (I have assumed that "best" means "lowest")

=AVERAGE(SMALL(--("0:"&SUBSTITUTE(A1:A5,".",":",1)),{1,2,3}))

Format your results as something like [m]:ss.00
--ron