One of the features of a new doctor's office will be a lavish waiting area. Patients in the waiting area consume coffee, snacks, magazines, and internet. As a result, the clinic incurs a cost of $30 per hour per patient using the waiting area. Nurses are able to service 20 patients per hour per nurse and patients arrive at an average rate of 18 per hour. Nurses receive $9 per hour in salary and benefits. 1. How many nurses should be on duty to minimize the clinic's total costs? [Select] 2. What is the total cost of waiting with 1 nurse? [Select] 3. What is the total cost of waiting with 2 nurses? [Select] 4. What is the total cost of waiting with 3 nurses? [Select] 5. If 2 nurses are staffed, what is the probability a new customer will wait for more than 6min? [Select] 6. If 2 nurses are staffed, what is the average time a patient will spend in the system? [Select]