Problem: A bakery wants to determine how many trays of doughnuts it should prepare each day. Demand is normal with a mean of 5 trays and standard deviation of 1 tray.
If the owner wants a service level of at least 95% how many trays should he prepare (round to the nearest whole tray)? Assume doughnuts have no salvage value after the day is complete.
A) 7
B) 5
C) 4
D) 6
E) Unable to determine with the above information.