Question

2. Patients arrive at a hospital accident and emergency department at random follow a

Poisson distribution at a rate of 6 per hour.
(a) Find the probability that, during any 90-minute period, the number of patients
arriving at the hospital accident and emergency department is
(i) exactly 7

(ii) at least 3

(b) What is the mean and standard deviation of the number of patients arriving at the
hospital accident and emergency department in an hour?

Answer 1

a )i) 0.117

ii)0.4126

b)0.7769