As the U.S. economy cools down, investors look to emerging markets to offer growth opportunities. In China, investments have continued to grow. Suppose that a random sample of 15 investments in U.S. corporations had an average annual return of 3.8% and standard deviation of 2.2%. For a random sample of 18 investments in China, the average return was 6.1% and the standard deviation was 5.3%. Conduct a test for equality of population means using α = 0.01.