A hotel wanted to develop a new system for delivering room service breakfasts. In the current system, an order form is left on the bed in each room. If the customer wishes to receive a room service breakfast, he or she places the order form on the doorknob before 11 P.M. The current system requires customers to select a 15-minute interval for desired delivery time (6:30-6:45 A.M., 6:45-7:00 A.M., etc.). The new system is designed to allow the customer to request a specific delivery time. The hotel wants to measure the difference between the actual delivery time and the requested delivery time of room service orders for breakfast. (A negative time means that the order was delivered before the requested time. A positive time means that the order was delivered after the requested time.) The factors included were the menu choice (American or Continental) and the desired time period in which the order was to be delivered (Early Time Period [6:30-8:00 A.M.] or Late Time Period [8:00-9:30 A.M.]). Ten orders for each combination of menu choice and desired time period were studied on a particular day. The data (stored in Breakfast) are as follows:

At the 0.05 level of significance,
a. Is there an interaction between type of breakfast and desired time?
b. Is there an effect due to type of breakfast?
c. Is there an effect due to desired time?
d. Plot the mean delivery time difference for each desired time for each type of breakfast.
e. On the basis of the results of (a) through (d), what conclusions can you reach concerning delivery time difference?
Discuss.

DESIRED TIME Early Time Period Late Time Period TYPE OF BREAKFAST 1.2 Continental Continental Continental Continental Continental Continental Continental Continental Continental Continental 2.5 3.0 0.2 1.2 3.3 3.4 5.3 2.2 0.7 1.3 0.2 -0.5 5.4 6.0 2.3 American American American American American American American American American American 4.8 5.5 5.6 9.5 7.9 9.4 4.9 4.0