To determine if the octane level of a gasoline influenced gas mileage, ten cars were driven over a 100-mile road test first using a 87-octane gas and then a 93-cotane gas. The miles/gallon measured for the ten cars were 87-octane: 17.6, 19.1, 18.3, 18.8, 19.5, 19.0, 18.1, 17.9, 19.2, 18.4 93-octane: 19.8, 19.2, 19.4, 18.9, 19.1, 20.0, 19.9, 20.3, 18.4, 18.6 Does increasing the octane increase the mileage?