8. Buy it again A consumer magazine plans to poll

Chapter 22, Problem 8

(choose chapter or problem)

8. Buy it again? A consumer magazine plans to poll carowners to see if they are happy enough with their vehiclesthat they would purchase the same model again.Theyll randomly select 450 owners of American-madecars and 450 owners of Japanese models. Obviously, theactual opinions of the entire population couldnt be known, but suppose 76% of owners of American cars and78% of owners of Japanese cars would purchase another.a) What sampling design is the magazine planning to use?b) What difference would you expect their poll to show?c) Of course, sampling error means the poll wont reflectthe difference perfectly. Whats the standard deviationfor the difference in the proportions?d) Sketch a sampling model for the difference in proportionsthat might appear in a poll like this.e) Could the magazine be misled by the poll, concludingthat owners of American cars are much happier withtheir vehicles than owners of Japanese cars? Explain.