How productive are employees? One way to answer this question is to study annual company profits per employee. Let x1 represent annual profit per employee in computer stores in St. Louis. A random sample of n1 =11 computer stores gave a sample mean of xbar1 = 25.2 thousand dollars profit per employee with sample standard deviation s1 = 8.4 thousand dollars. Another random sample of n2 = 9 building supply stores in St. Louis gave a sample mean xbar2 =19.9 thousand dollars per employee with sample standard deviation s2 = 7.6 thousand dollars. Does this indicate that in St. Louis, computer stores tend to have higher mean profits per employee? Use α = 0.01 and interpret your answer.