Thankyou very much

Hey, can any one help me please?

Sorry, I did type ro in the equation for ranges and not rho as above

I've tried that but then it tells me invalid input, no implementation of NonlinearFit matches the arguments in call. For example this is what i've typed:

g := NonlinearFit(E(F, alpha, ro, .31, 165, e), X, Y, F, parameterranges = list(alpha = 1 .. 100, rho = 1 .. 100))

Where am I going wrong in the above?