Answer to Question #72711 in Statistics and Probability for Danish

Question

Changes in airport procedures require considerable
planning. Arrival rates of aircraft are important
factors that must be taken into account. Suppose
small aircraft arrive at a certain airport, according to
a Poisson process, at the rate of 6 per hour. Thus, the
Poisson parameter for arrivals over a period of hours is
μ = 6t.
(a) What is the probability that exactly 4 small aircraft
arrive during a 1-hour period?
(b) What is the probability that at least 4 arrive during
a 1-hour period?
(c) If we define a working day as 12 hours, what is
the probability that at least 75 small aircraft arrive
during a working day?