1. The problem statement, all variables and given/known data Of the people passing through an airport metal detector, 0.5% activate it; Let X denote the number among a randomly selected group of 500 who activate it. 1) What is the PMF of X i) Using th CLT (approximate PMF) ii) Using the exact distribution of X 2) P(X = 5) using i and ii 3) P(X<=5) using i and ii 2. Relevant equations 3. The attempt at a solution So its been a while since Ive taking a probability class but I thought this was a Binomial Distribution problem where n = X, p = .005 and n = 500 P(X = x) = (500 Permutation X) * (.005^X) * (1-.005)^(500-X) but the output im getting for X = 1,2,3... = .20, .51, 1.29 which are clearly wrong. My thought for X = 1 would be P(X=1) = (1/500)*.005 = .00001 which seams reasonable to me but Im confusing myself when I go on to P(X = 2) Any hints would be appreciated.