8.14 Do you enjoy driving your car? The Pew Research Center recently polled n = 1048 U. S. drivers and found that 69% enjoyed driving their automobiles.
(a) Construct a 95% confidence interval for the proportion of U. S. drivers who enjoy driving their automobiles.
(b) In 1991, a Gallup Poll reported this percent to be 79%. Using the data from this poll, test the claim that the percent of drivers who enjoy driving their cars has declined since 1991. Report the large- sample z statistic and its P- value.
8.46 A comparison of the proportion of frequent binge drinkers. In the published report on binge drinking that we used for Example 8.1, survey results from both 1993 and 1999 are presented. Using the table below, test whether the proportions of frequent binge drinkers are different at the 5% level. Also construct a 95% confidence interval for the difference. Write a short summary of your results.
Year n X
1993 14,995 2,973
1999 13,819 3,140
The expert examines Pew Research on automobiles drivings.