Question

To test whether acetone improves fuel efficiency in passenger cars, 10 people were randomly selected. Each person brings his/her car to a gas station and fills it with gas. The car’s mileage is recorded. When the car is nearly empty, the person takes the car back to the gas station and refills it. Mileage and miles per gallon are recorded. Acetone is added to the tank. When the tank is nearly empty, the person returns to the gas station and fills the tank again. Miles per gallon are recorded. Below is a table with the data. [s_d = 1.011]

Driver	No Additive (mpg)	Additive (mpg)	Difference (d)
1	18.4	19.0
2	23.5	22.8
3	31.4	30.9
4	26.5	26.9
5	17.2	28.4
6	16.3	18.2
7	19.4	19.2
8	20.1	21.4
9	14.2	16.1
10	22.1	21.5

1. What is the null hypothesis? (1 point)

2. What is the alternative hypothesis? (1 point)

3. Is it a one-tailed or two-tailed test? (1 point) (1 point)

4. What test statistic should you use? (1 point)

5. Calculate the appropriate standard error. (Round to three decimal places.) (1 point)

6. Calculate the appropriate test statistic. (Round to three decimal places.) (1 point)

7. Calculate the degrees of freedom. (1 point)

8. Using an alpha of 0.10, what is the critical value(s)? (1 point)

9. Based on the test statistic and critical value, what is your decision? (1 point)

10. The results are/are not statistically significant at an alpha level of ______ and we conclude __________________ (research question). (1 point)

Answer 1