I fitted some data using the trend line tool. The fit purportedly was a 3-rd
order polynmial. When I create a column of values using the coefficients
that Excel found (Display equation), I find the data does not overlay the
trend line. I created data in the range of the fit so there is no error due
to extrapolation and the fit R value was 0.9999. Is there an error in the
routine that reports the coefficients for polynomial fits? If so, is the re
a patch or work around?

Thanks