Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions
A researcher wanted to determine if using an octane booster would increase gasoline mileage. A random sample of seven cars was selected; the cars were driven for two weeks without the booster and two weeks with the booster. Use the definitions of X₁ and X₂ as given in the table. Consequently, D = X₁-X₂.
-What critical value should be used at α = 0.05?

A) -2.447
B) -2.365
C) -1.943
D) -1.895