Your son has put you one the right track with the trendline. But look at the
first three terms in the equation y = 2E-16x4 + 2E-11x3 + 8E-06x2 + 0.6827x
+ 731.29
They are so small compared to the others that I think you would be better
of with just two terms y = 0.6827x + 731.29 UNLESS you have some very large
x values.

To get the slope value in a cell use =SLOPE(y-value-range, x-value-range).
Lets say this is in D10
To get intercept use =INTERCEPT(y-value-range, x-value-range). Lets say
this is in E10
To find y's value when x=3: put 3 in F10 and in G10 use =F10*D10+E10 (the
equation of a straight line is y=mx+b)

If you want more terms use LINEST. Visit
www.stfx.ca/people/bliengme/ExcelTips on how to do this
best wishes
--
Bernard V Liengme
www.stfx.ca/people/bliengme
remove caps from email

"Tatsukun" wrote in
message ...

Thanks, that seems to work for some of the cells, but I get a lot of Y
values of "N/A".

To clarify, I want to enter X values that are not already entered, and
have Excel calculate a Y (or a reasonable guess thereof).

So for example, if my X values are 2,4,6,8, and 10; and my
correcponding Y's are 10,20,30,40, and 50 respectivly, I want to be
able to input something like "X=3" and get out "Y=15".

I really wish I knew enough about this stuff to make sence trying to
explain my problem.

I asked my son, he got me as far as a scatter graph, and a Trendline.
So I got this really hard looking formula...

y = 2E-16x4 + 2E-11x3 + 8E-06x2 + 0.6827x + 731.29

Can I just make Excel work that out somehow?

Thanks!

-Tatsu


--
Tatsukun
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