Hi Poisson Distribution: λ = 1/3 Using TI or similarly an inexpensive calculator like a Casio fx-115 ES plus (a) P(X = 0) = poissonpdf(1/3, 0)= .7165 Or = ((1/3)^0/0!)*e^(-1/3)}}} = .7165 (b) P(X ≥ 4) = 1 - P(X ≤ 3) = 1 - .0044 = .9956 Or long hand:P(x = 0) + P(x = 1) + P(x = 2) + P(x = 3) Wish You the Best in your Studies.