Melanie is the manager of the Clean Machine car wash and has gathered the following information. Customers arrive at a rate of ? = 6 cars per hour according to a Poisson distribution. The car wash machine has a service rate that follows an exponential distribution = 8 cars per hour . Assume the car wash is operational 10 hours per day .

The average service time for the car wash machine is 8 cars per hour.

True or false?

The probability that exactly 4 customers arrive in one hour is more than 12%.

True or false?

The probability that it takes less than fifteen minutes to wash a car is less than 85%.

True or false?

The average number of customers in the queue is 2.25 .

True or false?

The average total time for a customer to be at the car wash is 30 minutes

True or false?

The probability that there are exactly 4 customers in the system is about 7.9% .

True or false?