Your town is interested in the proportion of teenagers who do NOT favor the elimination of a local curfew on teenagers. Assume your town has 2,000 teenagers.
A. To generate a 90% confidence interval for the proportion of students who do NOT favor the elimination of a curfew, what's the minimum number of teenagers you need if you want the margin of error to be 6%?
B. Suppose your mayor, who never took a statistics class, says that a 6%
margin of error just isn't accurate enough. She wants you to produce a
confidence interval with a margin of error of only 2%. How big does your
sample have to be now? What do you think of the mayor's proposal?
C. In general, if you wanted to cut the margin of error for a given confidence level
to one third of the original 6%, by what factor would you have to increase the sample size? Use the formula for minimum sample size to explain your answer.