Comparing gas brands The marketing department of a major oil company wants to investigate whether cars get better mileage using its gas (Brand A) than from an independent one (Brand B) that has cheaper prices. The department has 20 cars available for the study.

a. Identify the response variable, the explanatory variable, and the treatments.

b. Explain how to use a completely randomized design to conduct the study.

c. Explain how to use a matched-pairs design to conduct the study. What are the blocks for the study?

d. Give an advantage of using a matched-pairs design.