Answer Happy

During a test period, an experimental group of 16 vehicles using an 85% ethanol-gasoline mixture showed mean CO2 emissions of 243 pounds per 100 miles, with a standard deviation of 27 pounds. A control group of 13 vehicles using regular gasoline showed mean CO2 emissions of 231 pounds per 100 miles with a standard deviation of 14 pounds. At a = 0.03, assuming unequal variances, in a right-tailed test we conclude that the experimental ethanol-gasoline mixture did not statistically change the average CO2 emissions. increased the average CO2 emissions. O None of these reduced the average CO2 erkissions.