Chris -

(1) Using a polynomial of order more than 2 or 3 often results in
overfitting. Interpolation may (or may not) be useful, but extrapolation is
likely to be useless.

(2) Here's one way to calculate y for a new x:

=TREND(known_y,known_x^{1,2,3,4,5,6},new_x^{1,2,3, 4,5,6})

- Mike Middleton
http://www.DecisionToolworks.com
Decision Analysis Add-ins for Excel


"Chris" wrote in message
...
When I calculate a trendline, I get a 6 degree polynomial. How do I
calculate
a value using this formula? I have no idea how to compute the capital
"E" - I
don't think it's Euler's number and it doesn't look like scientific
notation
to me...

"y = -1E-07x^6 + 0.0016x^5 - 7.9878x^4 + 20857x^3 - 3E+07x^2 + 2E+10x -
8E+12
"
Thanks for your help!