You may want to check
Trendline Coefficients and Regression Analysis
http://www.tushar-mehta.com/publish_...nalysis/16.htm


On Fri, 25 Jul 2008 11:49:32 -0700, john s
wrote:

I am using trendline feature in charting to develop a third order
polynomial
equation. The fit is good and I want to use the displayed equation to
calculate nondata point values.
I cannot get the equation to generate points within the original data
set.
Is there a conversion factor I need to use or is there a way to output
the
trendline equation differently? The trendline coefficients don't seem
to
correspond to the data set even though the graph and r-value look
good.

Regards,

Tushar Mehta
Microsoft MVP Excel 2000-2008
www.tushar-mehta.com
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