The supervisor at the Precision Machine Shop wants to determine the staffing policy that minimizes total operating costs. The average arrival rate at the tool crib: where tools are dispensed to the workers, is 5 machinists per hour. Each machinist's pay is $5 per hour. The supervisor can staff the crib either with a junior attendant who is paid $9 per hour and can process 10 arrivals per hour or with a senior attendant who is paid $19 per hour and can process 16 arrivals per hour. Which attendant should be selected?

The should be selected, with a total estimated hourly cost of (Enter your response rounded to two decimal places.)