(a)[1]
State one further condition for the number of customers arriving per minute to have a Poisson distribution.
(b)[2]
It is now assumed that the number of customers arriving per minute has the distribution $\mathrm{Po}(2.3)$. Find the probability that exactly 3 customers arrive in a 1-minute interval.
(c)[3]
Find the probability that more than 3 customers arrive in a 2-minute interval.
(d)[3]
Five 1-minute periods are selected at random. Find the probability that no customers arrive in exactly 2 of these 5 periods.