How do different distributions of random input have an effect on output results in a simulated physical model?

Statistical methods are practical and unavoidable in analysis of physical and engineering results‎. ‎Study of anufacturing errors and uncertainties in construction of radio frequency structures is one of cases which statistical quantities is used‎. ‎In this paper‎, ‎we quantify uncertainty in the cutoff frequency of a waveguide using the chaos polynomial expansion method‎. ‎Different distributions for uncertainty in the waveguide width are considered‎. ‎We then investigate the effect of the distributions on the waveguide cutoff frequency‎. ‎Using statistical quantities‎, ‎we determine the amount of acceptable error during the construction of the waveguide such that it does not affect the wavequide performance.