You can find an EXCEL file here that can be used to generate the logistic model for the United States population size (from the Census 1790-1940). I used Solver to obtain the logistic model. I showed how to use Solver to obtain an exponential model in a previous posting. In that posting, I used Solver to find values of two constants,a and b, for f(x)=ae^bx so that the sum (or average) of square differences is minimized. For the logistic model, you need to find constants a, b, and c for g(x)=c/(1+ae^-bx) so that the average (or sum) of the square differences between the raw data and g(x) is minimized. At some point in the future, I'll post a detailed tutorial on how to do this.

In the class project, we used an exponential model based on data from 1790-1860. If you want to see an EXCEL file that additionally considers an exponential model based on data from 1790-1940, click here.