compare separate data sets

[Daddio]

I regularly plot x-y graphs of a spring's force vs
height. Height is X; force is Y. This data is acquired
somewhat arbitrarily--I never really know what exact x
values will end up in my table. So when I want to compare
two springs at any specific height, I have to either
guesstimate based on the chart or find values that match
close enough. I have also written specific FORECAST
functions to find the comparison points between two real
data points. But geez that takes too long!
How can I take multiple x-y tables with any ol' values in
x, and (what's the word?) normalize them to have the same
x values? (Clear as mud?)
Thanks in advance!
D²

 

[Marcy]

Daddio,
For a rookie at this, I'm not so sure about "clear as
mud", but you gave me some info I can sit down with
someone and see what we can figure out. I was told it
couldn't be done.

Thanks!