Try this:

With
A1:O1 containing numbers or blanks

These formulas average every 3rd non-blank cell,

beginning with cell A1
A2: =AVERAGE(IF((A1:O1<"")*(MOD(COLUMN(A1:O1),3)=1),A 1:O1))

beginning with cell B1
A2: =AVERAGE(IF((A1:O1<"")*(MOD(COLUMN(A1:O1),3)=2),A 1:O1))

beginning with cell C1
A2: =AVERAGE(IF((A1:O1<"")*(MOD(COLUMN(A1:O1),3)=0),A 1:O1))

Is that something you can work with?
***********
Regards,
Ron

XL2002, WinXP


"LostwithoutLost" wrote:

Hi there, thanks for all your help in advance. I am looking for a formula
that will average every 3rd entry on a row of data. I would like to set it
up so that it ignores empty cells. chris