Answer:
28.65% probability that the next customer will not arrive for 5 minutes
Explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given time interval.
Mean of 15 customers an hour:
An hour has 60 minutes, so in the space of 5 minutes, the mean is:

A customer walks in what is the probability that the next customer will not arrive for 5 minutes?
This is P(X = 0).


28.65% probability that the next customer will not arrive for 5 minutes