Fewer young people are driving. in 1983, 87% of 19-year-olds had a driver’s license. twenty-five years later that percentage had dropped to 75% (university of michigan transportation research institute website, april 7, 2012). suppose these results are based on a random sample of 1200 19-year-olds in 1983 and again in 2008. a. at 95% confidence, what is the margin of error and the interval estimate of the number of 19-year-old drivers in 1983? b. at 95% confidence, what is the margin of error and the interval estimate of the number of 19-year-old drivers in 2008? c. is the margin of error the same in parts (a) and (b)? why or why not?