User`s guide

1 Getting Started with the Curve Fitting Toolbox
1-10
Because the goal of fitting the census data is to extrapolate the best fit to
predict future population values, you should explore the behavior of the fits up
to the year 2050. You can change the axes limits of the Curve Fitting Tool by
selecting the menu item
Tools->Axes Limit Control.
The census data and fits are shown below for an upper abscissa limit of 2050.
The behavior of the sixth degree polynomial fit beyond the data range makes it
a poor choice for extrapolation.
As you can see, you should exercise caution when extrapolating with
polynomial fits because they can diverge wildly outside the data range.
The sixth degree polynomial fit
beyond the data range makes it
a poor choice for extrapolation.
Change the upper abscissa
limit to 2050.