Interpreting Calculator Display The Insurance Institute of America wants to estimate the percentage of drivers aged 18-20 who drive a car while impaired because of alco- hol consumption. In a large study, 42,772 males aged 18-20 were surveyed, and 5.1% of them said that they drove in the last month while being impaired from alcohol (based on data from "Prevalence of Alcohol-Impaired Driving," by Liu, Siegel, et al, Journal of the American Medical Association, Vol. 277, No. 2). Using the sample data and a 95% confidence level, the TI-83 Plus calculator display is as shown.
a. Write a statement that interprets the confidence interval.
b. Based on the preceding result, does alcohol-impaired driving appear to be a problem for males aged 18-20? (All states now prohibit the sale of alcohol to persons under the age of 21.)
c. When setting insurance rates for male drivers aged 18-24, what percentage of alcohol-impaired driving would you use if you are working for the insurance company and you want to be conservative by using the likely worst case scenario?