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 MichiganTransportation Research Institute website, April 7, 2012). Suppose these results are basedon 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 numberof 19-year-old drivers in 1983?b. At 95% confidence, what is the margin of error and the interval estimate of the numberof 19-year-old drivers in 2008?c. Is the margin of error the same in parts (a) and (b)? Why or why not?

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2-Proportion Test

In a 2-proportion test, two separate proportions are measured at the same time, and their similarity is evaluated. It is also known as a 2-proportion z-test, and a comparison of two different proportions is done in this method.