I am trying to fit a function to some data which represents the number of observations at a given life.
The function I would like to fit is b*Exp[-a*x]. However, when I use the two different fit methods (as shown in the attached .nb file) there are two different results.
The reason I ask is that I would like to include another term in the fit function so it is of the form b*Exp[-a*x] + c.
The fit result from the GeneralizedLinearModelFit seems to fit much better than the one from NonlinearModelFit.
My question is: how can I get Mathematica to give the same result for both functions so I can add a constant term to the NonlinearModelFit function?
Attachment: lifetime.nb, URL: ,