Answer:
1.56499409
Step-by-step explanation:
We solve using Poisson Distribution
P = λ^k × e^-λ/k!
λ is the average of events = mean rate of 2 cars per half an hour = 2 × 2 = 4
e is the euler's number
k is the number of events you want to know the probability = no more than 4
= ≤ 4
Hence:
P(≤ 4) = 4^4 × e^-4/4! + 4^3 × e^-4/3! + 4^2 × e^-4/2! + 4^1× e^-4/1! + 4^0× e^-4/0!
P(≤ 4) = 0.1953668148 + 0.1953668148 + 1.0826822659 + 0.0732625556 + 0.0183156389.
P(≤ 4) = 1.56499409
