Poisson distribution
Probability theory · Mathematics
Study notes
Q: Calls arrive at 3 per hour. Find P(exactly 2 calls in an hour). λ = 3, k = 2. P(X=2) = e^(-3) × 3^2 / 2! = e^(-3) × 9/2. e^(-3) = 0.0498. P = 0.0498 × 4.5 = 0.224. About 22.4% chance of exactly 2 calls.