Question

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 1,650 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 four decimal places.

Margin of error =  

Interval estimate =   to  

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.

Margin of error =  

Interval estimate =   to  

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

Answer 1