oerliPoisson PMF
P(X = k) = exp(-ฮป)ยทฮป^k/k! and cumulative P(X โค k) for Poisson(ฮป).
P(X = k) = 0.21376301724973648
P(X โค k) = 0.7575761331330659
P(X = k) = exp(-ฮป)ยทฮป^k/k! and cumulative P(X โค k) for Poisson(ฮป).
P(X = k) = 0.21376301724973648
P(X โค k) = 0.7575761331330659