Answer:
0.1535 = 15.35% probability that at least one customer arrives in a particular one minute period.
0.1443 = 14.43% probability that at least two customers arrive in a particular 4 minute period.
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 interval.
Find the probability that at least one customer arrives in a particular one minute period.
The average is of 10 customers per hour(60 minutes), so for this case,

This is:

In which



0.1535 = 15.35% probability that at least one customer arrives in a particular one minute period.
Probability that at least two customers arrive in a particular 4 minute period.
The average is of 10 customers per hour(60 minutes), so for this case,

This probability is:

In which

So





0.1443 = 14.43% probability that at least two customers arrive in a particular 4 minute period.