Morning

1. Consider the following results for independent samples taken from two populations. If n1= 400 with p1 = 0.48 and n2 = 300 with p2 = 0.36. a. What is the point estimate of the difference between the two population proportions? b. Develop a 90% confidence interval for the difference between the two population proportions. 2. A sample of parts provided the following contingency table data on part quality by production shift. Use a = 10% and test the hypothesis that part quality is independent of the production shift. What is your conclusion? Number Number Shift Good Defective First 368 32 Second 285 15 Third 176 24 3. Since 2000, the Toyota Camry, Honda Accord, and Ford Taurus have been the three bestselling passenger cars in the United States. Sales data for 2003 indicated market shares among the top three as follows: Toyota Camry 37%, Honda Accord 34%, and Ford Taurus 29% (The World Almanac, 2004). Assume a sample of 1200 sales of passenger cars during the first quarter of 2004 shows the following. Passenger Car Units Sold Toyota Camry 480 Honda Accord 390 Ford Taurus 330 Can these data be used to conclude that the market shares among the top three passenger cars have changed during the first quarter of 2004? What is the p-value? Use a 0.05 level of significance. What is your conclusion