Peanut brittle. A food scientist wishes to study the effect of the type of pan and amount of sodium bicarbonate used in preparing peanut brittle on the flavor of the peanut brittle. In an experiment, peanut brittle is baked in four types of pans (iron, aluminum, stainless steel, and nonstick stainless steel) using 0, 2, or 4 grams of sodium bicarbonate in the recipe. Ten batches of peanut brittle are prepared at each combination of pan type and amount of sodium bicarbonate. A panel of tasters scores each batch on the intensity of peanut, sweet, and buttery flavors.
(a) What are the explanatory variables and the response variables for this experiment?
(b) Make a diagram like Figure 6.1 to describe the treatments. How many treatments are there? How many batches of peanut brittle are needed?
(c) Explain why it is a bad idea to bake all 10 batches for one treatment at once, then bake the 10 batches for the second treatment, and so on. Instead, the experimenters will bake the batches in a random order.
Figure 6.1
