Ikarus, the Hungarian bus maker, lost its important Commonwealth of Independent States market and is reported on the verge of collapse. The company is now trying a new engine in its buses and has gathered the following random samples of miles-per-gallon figures for the old engine versus the new:

Is there evidence that the new engine is more economical than the old one?

Old engine 8,9, 75, 8.5, 6, 9,9, 10, 7, 8.5, 6, 10, 9, 8, 9, 5, 9.5, 10, 8 New engine: 10,9, 9, 6,9, 11, 11, 8, 9, 6.5, 7,9, 10, 8,9, 10, 9, 12, 11.5, 10, 7, 10, 8.5