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. Miles / GalMiles / Gal Without With 23.99 29.05 24.47 26.01 25.7 26.33 25.12 28.11 21.06 29.33 21.56 29.44 22.8 26.5 Determine the difference between the sample mean mileage of the cars that are driven without a booster and with a booster. O 11.764 O 4.296 O -4.296 O 11.764