I have to fit many large datasets into a linear equation. I am using the following code, employing NonlinearModelFit to avoid the Gaussian error propagation since the parameter of interest is c (if I were to use the linear fit i would have to multiply the slope with n and propagate the error since n itself isn’t an exact quantity). I know the values of n (one per dataset) and I want Mathematica to automatically include its uncertainty into the fittet model, so that I get the uncertainty of c in the paramtertable, with the uncertainty of n taken into account.

NonlinearModelFit = [data, (c/n) x + d, {c, d}, x]