This does not seem to be working. Is anything wrong with the values of parameters? I am getting these values for alpha and beta. Could you please tell me why this is happening?
{{Piecewise[{{(6.62729289400781106065850404419402`12.345130730619111*^-1547*x^328.31)/E^(0.002429366178364065*x), x > 0}}, 0]}}
Looking at some values
data /. x -> 1 (*{{6.611212313514908*10^-1547}}*)
data /. x -> 100 (*{{2.166856405198*10^-890}}*)
So the values are all practically zero. That is why you do not see them. Mathematica is having hard time plotting such small values since if Chop them, they are zero Chop[data /. x -> 1] gives zero.