Four cake recipes are to be compared for moistness. The researcher will conduct the experiment by preparing and then baking the cake. Each preparation of a recipe makes only one cake. All recipes require the same cooking temperature and the same length of cooking time. The oven is large enough that four cakes may be baked during any one baking period, in positions P1 through P4, as shown here.

a. Discuss an appropriate experimental design and randomization procedure if there are to be r cakes for each recipe.
b. Suppose the experimenter is concerned that significant differences could exist due to the four baking positions in the oven (front vs. back, left side vs. right side). Is your design still appropriate? If not, describe an appropriate design.
c. For the design or designs described in (b), suggest modifications if there are five recipes to be tested but only four cakes may be cooked at any one time.

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