The number of people arriving for treatment at an emergency

The number of people arriving for treatment at an emergency room can be modeled by a Poisson process with a rate parameter of four per hour.

(a) What is the probability that exactly two arrivals occur during a particular hour? (Round your answer to three decimal places.)


(b) What is the probability that at least two people arrive during a particular hour? (Round your answer to three decimal places.)


(c) How many people do you expect to arrive during a 45-min period? _______ people.

Solution

X - no of people arriving for treatment at emergency is poisson with mean = 4

a) P(x =2) = 0.1465

b) P(X>=2) = 0.9084

c) For 45 minutes period expected people = 4x45/60 = 3