Make sure in both cases you use an XY chart, not a line chart. Also, expand
the number format of the regression formula to display as many digits as
possible, using a scientific format with lots of decimal places,

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"SPWelch" wrote in message
...
I made a scatter chart of some data in Excel 2007 and placed a power fit
trendline that resulted in the equation y=0.075x^-0.06 with a R^2 of
0.983.
If I try to back calculate data points based on this model I get values
that
differ from the input data. I took the exact same data in Excel 2003 and I
get a different equation (y=0.1001x^-0.0572) and R^2 (0.9931). I used this
equation to back calculate some input values and it worked perfect. Is
there
an error with the equation reporting routine in Excel 2007? My OS is XP
HOME
SPII



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