I am trying to fit a non-linear formula to a set of data in Excel 2007. I
use the trendline feature and have selected several different formulas. On
my chart, the trendline matches my data very well.

But, the formula that is displayed does not mathematically fit my data at
all. When I place in my variables into the formula Excel provided, my
predicted values are way off the chart.

What am I doing wrong and how do I fix this?