Comhroinn Fuaime

This problem deals with the number of events occurring within a fixed period with a known average value, so we use the Poisson distribution. In Excel, we apply the function POISSON.DIST(x, λ, cumulative), where 𝑥 x (read: x) is the number of occurrences, 𝜆 λ (read: lambda) is the mean, and the cumulative argument determines the type of probability calculated. Specifically, FALSE is used to compute the probability of exactly 𝑥 x, written as 𝑃 ( 𝑋 = 𝑥 ) P(X=x) (read: P of X equals x), wh