For large U.S. companies, what percentage of their total income comes from foreign sales? A random sample of technology companies (IBM, Hewlett-packar information. t Technology companies, % foreign revenue: x,; n, = 16 62.8 55.7 47.0 59.6 55.3 41.0 65.1 51.1 53.4 50.8 48.5 44.6 49.4 61.2 39.3 41.8 Another independent random sample of basic consumer product companies (Goodyear, Sarah Lee, H.J. Heinz, Toys 'R' Us) gave the following information. Basic consumer product companies,% foreign revenue: X,; n, = 17 28.0 30.5 34.2 50.3 11.1 28.8 40.0 44.9 40.7 60.1 23.1 21.3 42.8 18.0 36.9 28.0 32.5 LO USE SALT Assume that the distributions of percentage foreign revenue are mound-shaped and symmetric for these two company types. (a) Use a calculator with mean and standard deviation keys to calculate x] , S1, X2, and s2. (Round your answers to four decimal places. ) x , % S 1 X, = S , = (b) Let , be the population mean for x, and let /2 be the population mean for x2. Find a 90% confidence interval for , - M2. (Round your answers to tv lower limit upper limit %