During a test period, an experimental group of 10 vehicles using an 85 percent ethanol-gasoline mixture showed mean CO2 emission
s of 667 pounds per 1000 miles, with a standard deviation of 20 pounds. A control group of 14 vehicles using regular gasoline showed mean CO2 emissions of 679 pounds per 1000 miles with a standard deviation of 15 pounds. At α = 0.05, in a left-tailed test (assuming equal variances) the test statistic is:______. A. 1.321.
B. -2.508.
C. -2.074.
D. -1.717.
Since ZY bisects GE and XY bisects EF, and both ZY and XY both bisect GF, then XY ~ ZE and ZY ~ XE. Therefore ZE = XY = 5 And GE = 2× ZE (because bisected segments are = and therefore ×2 = long segment). So GE = 2ZE = 2×5 = 10
