dolution

Many fast-food restaurants use automatic soft-drink dispensing machines that fill cups once an order is placed at a drive-through window. A regional manager for a fast-food chain wants to determine if the machines in his region are dispensing the same amount of product. He samples four different machines and measures a random sample of 16-ounce drinks from each machine.

(a) Do the data indicate that the mean amount dispensed from the machines is not the same? Use an  level of significance.

(b) Use Tukey’s test, if necessary, to determine which pairwise means differ using a familywise error rate of

(c) Draw boxplots of the four treatment levels to support your conclusions in parts (a) and (b).