Need a formula to average every other value in a column.

[Coach J]

I have columns with 100+ values. I need averages of the odd numbered rows
and then averages of the even numbered rows. Any ideas?

 

[Gary''s Student]

for the even rows:

=AVERAGE(IF(MOD(A1:A100,2)=0,A1:A100)) as an array formula

for the odd rows:

=AVERAGE(IF(MOD(A1:A100,2)=1,A1:A100)) as an array formula

 

[Dave Peterson]

I'd use:

Odd Rows:
=AVERAGE(IF((ISNUMBER(A1:A100)*MOD(ROW(A1:A100),2))=1,A1:A100))

Even Rows:
=AVERAGE(IF((ISNUMBER(A1:A100)*MOD(ROW(A1:A100),2))=0,A1:A100))

Both array entered.