The tool crib at a large manufacturing company is responsible for providing tools to the factory workers on demand. The tool crib has a variable demand. Historically, its demand has ranged from 320 to 570 small tools per day with an average of 445. Diane, the tool crib attendant, works eight hours a day, five days a week. Each order is for one small tool and each small tool takes Diane 1 minute to retrieve from the bins.

What is the average waiting time, in minutes?

6.4 5.4 7.4 1