formula for averages

[JNSteiner]

I have to compute the last 15 scores and obtain an aveage for Special
Olympics entry. I want to be able to have a formula which goes up the column
until it adds 15 games. There will be blanks as the athletes do not come
every week. So 15 games for one bowler will not be in the same row entries
as another. I know there must be a waty to do this but I don't have a clue
how. Can someone help? Last year I manually chose the 15 cells to add but
this year I have twice as many athletes. Thanks!

 

[Lars-Åke Aspelin]

I have to compute the last 15 scores and obtain an aveage for Special
Olympics entry. I want to be able to have a formula which goes up the column
until it adds 15 games. There will be blanks as the athletes do not come
every week. So 15 games for one bowler will not be in the same row entries
as another. I know there must be a waty to do this but I don't have a clue
how. Can someone help? Last year I manually chose the 15 cells to add but
this year I have twice as many athletes. Thanks!

Assuming that your 15 last scores are to be found in the first 100
rows of column A and that there are always at least 15 scores present,
try this formula:

=AVERAGE(IF(ROW(A1:A100)*(A1:A100<>"")>=LARGE(ROW(A1:A100)*(A1:A100<>""),15),A1:A100))

Note: This is an array formula that must be confirmed by
CTRL+SHIFT+ENTER rather than just ENTER.

Hope this helps / Lars-Åke

l