Mr. B, the manager of the retail store in Exercise 12. .44, has seen that the mean number of customers per day and the mean number of items purchased (Exercise
12. .45) are affected by the month, and he is now wondering if month has a similar effect on the total cost of items purchased.
a. Do you think “month” has an effect on the mean total cost of items purchased per day? Equivalently, do you think the mean total cost of items purchased per day is the same for all months? If not, which months do you believe are different? Explain.
b. Construct a dotplot for the total cost of items purchased per day for each different month.
c. Does the dotplot in part b support your conjectures in part a? Explain.
d. Use the ANOVA technique to answer the question, “Does month affect the mean total cost of items purchased per day?” Usea. = 0.05.
e. Explain any differences and similarities between your answer in part a and the answer found in part d.
f. Explain any differences and similarities between the answers found for Exercises 12. .44, 12. .45, and 12. .46. Do the similarities seem reasonable? What does this imply about these variables?