CommandsStatsWaldPDFOn this pageStatsWaldPDF StatsWaldPDF (x, µ, λ) The StatsWaldPDF function returns the inverse Gaussian or Wald probability distribution function f(x;μ,λ)=λ2πx3exp[−λ(x−μ)22μ2x].\displaystyle f(x ; \mu, \lambda)=\sqrt{\frac{\lambda}{2 \pi x^{3}}} \exp \left[-\frac{\lambda(x-\mu)^{2}}{2 \mu^{2} x}\right] .f(x;μ,λ)=2πx3λexp[−2μ2xλ(x−μ)2]. where x, µ, λ > 0. See Also Statistical Analysis, StatsWaldCDF