The table below describe the gas mileage (in miles per gallon) of 8 cars with as well as without using the fuel additive. At a = 0.10, is there enough evidence to conclude that fuel additive improved gas mileage?
Car 1 2 3 4 5 6 7 8
without 35.8 37.7 39.4 36.8 36.6 33.7 38.4 37.3
with 36.2 39.8 40.1 39.3 36.9 34.5 38.8 39.1