Editors of the business report in given Exercise are willing to accept a margin of error of 4% but want 99% confidence. How many randomly selected employers will they need to contact?
Exercise :
Hiring. In preparing a report on the economy, we need to estimate the percentage of businesses that plan to hire additional employees in the next 60 days.
a) How many randomly selected employers must we contact in order to create an estimate in which we are 98% confident with a margin of error of 5%?
b) Suppose we want to reduce the margin of error to 3%. What sample size will suffice?
c) Why might it not be worth the effort to try to get an interval with a margin of error of only 1%?