Fewer young people are driving. In 1983, 87 percent of 19 year-olds had a driver's license. Twenty-five years later that percentage had dropped to 75 percent (University of Michigan Transportation Research Institute website, April 7, 2012). Suppose these results are based on a random sample of 1200 nineteen 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 nineteen year old drivers in 1983? Round your answers to three decimal places.

b. At 95% confidence, what tis the margin of error and the interval estimate of the number of nineteen year old drivers in 2008? Round your answers to four decimal places.

c. Is the margin of error the same in parts (a) and (b)?