Let's say your data is in A1:A100 with row 1 containing labels.
A has the x-values, B the y-values
In C2 enter =IF(MOD(ROW()-1,3)=0,B2,NA())
Copy this down to C100
Select A1:A100, hold CTRL, select C1:C100
(Control key used to select non-contiguous data)
Make chart in normal way; Excel will ignore the NA values

If first x-value is in A1 use =IF(MOD(ROW(),3)=0,B1,NA())
If first x-value is in A2 use =IF(MOD(ROW()-1,3)=0,B2,NA())
If first x-values is in A3 use =IF(MOD(ROW()-2,3)=0,B3,NA())
If first x-value in A4 use =IF(MOD(ROW(),3)=0,B4,NA())
get the picture?

best wishes
hope you recover from your XL-distemper!
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"notquitefedupwithxl" wrote
in message ...
I wasn't able to locate how to solve the following problem, so I thought
I'd
post it he

I have a 2 long columns of data points (XY scatter format). I want to
plot
only every 3rd XY pair. Aside from manually selecting every third data
point
with ctrl+left mouse click, is there an easier way?