Question

Listed below are the combined city – highway fuel consumption ratings (in miles per gallons) for different cars measured in old rating system and cars in a new rating system introduced in 2008 (based on data from USA today).

A. Construct a 90 percent confidence interval of the difference in the ratings of cars.

Old Rating: 16 18 27 17 33 28 33 18 24 19 18 27 22 18 20 29 19 27 20 21

New Rating: 15 16 24 15 29 25 29 16 22 17 16 24 20 16 18 26 17 25 18 19

B. Based on the interval is there a reason to believe that there is a difference in the ratings of the two cars?

C. Is there any significant difference in the old and new ratings of cars? Use appropriate hypothesis test to answer this question.

Answer 1