Suppose we know that the proportion of high school students in the U.S. that smoke is .10. We now visit the local high school and sample 50 students and find that 20 students smoke.
(A) Construct a 95% Confidence Interval.
(B) Is the smoking behavior at the local high school different than at the national level?
(C) Using the national average, what is the probability of observing a school where the proportion of students that smoke is .40?