A clinic has only one dentist. During working days, the traffic is uniformly busy with patients arriving at the rate of 8 patients per hour. The doctor's service time is 3 minutes. (Please keep three digits after the decimal and do not omit 0 before the decimal, good example: 0.132) 1. What is the probability that the clinic is empty (except for the dentist)? 2. What is the average number of patients in the waiting room? 3. What is the average time (in minutes) a patient spends in the office (wait plus service)? 4. What is the probability that the clinic has exactly two patients