Astudy by allstate insurance co. finds that 82% of teenagers have used cell phones while driving (the wall street journal, may 5, 2010). in october 2010, massachusetts enacted a law that forbids cell phone use by drivers under the age of 18. a policy analyst would like to determine whether the law has decreased the proportion of drivers under the age of 18 who use a cell phone.
a. state the null and the alternative hypotheses to test the policy analyst’s objective.
b. suppose a sample of 200 drivers under the age of 18 results in 150 who still use a cell phone while driving. what is the value of the test statistic? what is the p-value?