Question: An automobile manufacturer markets the same vehicle in Europe and the U.S., but buyer quality ratings are different. Based on a sample of 100 vehicles in each market, a mean quality rating of 4.3 was reported in the U.S. compared to a mean rating of 3.7 in Europe. What test(s) should be used to determine if there is a significant quality difference in the two markets, assuming that a significance level of 5% is required?