Fewer young people are driving. In 1983, 87 percent of 19 year-olds had a driver’s license.

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 percentage of nineteen year old drivers in 1983? Round your answers to three decimal places.

Margin of error =  (four decimal places)

Interval estimate =  to 

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

Margin of error = 

Interval estimate =  to 

c. Is the margin of error the same in parts (a) and (b)?- Select your answer -YesNoItem 7

Why, or why not?