At the Billy Goat Gruff Inn, Machines Are Set to Dispense

Essay

At the Billy Goat Gruff Inn, machines are set to dispense 600 ml of soda into every
customer's glass. Over time, however, the machine can get "out of control" and dispense too
much soda or too little. The machine needs adjustment if the mean amount dispensed is
different than 600 ml. At a randomly selected time each clock hour, the owner dispenses and
checks a glass of soda and determines the actual volume of soda dispensed. One day the
volumes (in ml) of the dispensed soda were: $$600.15,599.92,599.85,599.92,599.81,600.14,600.04,599.98$$ Is there sufficient evidence to conclude that the dispensing machine needs adjustment?