7.2 Cars arrive at a car wash according to a Poisson process with a mean rate of eight cars per hour. The policy at the car wash is that the next car cannot pass through the wash procedure until the car in front of it is completely finished. The car wash has a capacity to hold 10 cars, including the car being washed, and the time it takes a car to go through the wash process is exponentially distributed with a mean of 6 min. What is the average number of cars lost to the car wash company every 10-h day as a result of the capacity limitation?