We guess, based on historical data, that 30% of graduating high-school seniors in a large city will have completed a first-year calculus course. What's the minimum sample size needed to construct a 95% confidence interval for a proportion with a margin of error of 2.5%?

A. 1,537
B. 1,290
C. 323
D. 1,291
E. 1,536

Question

We guess, based on historical data, that 30% of graduating high-school seniors in a large city will have completed a first-year calculus course. What's the minimum sample size needed to construct a 95% confidence interval for a proportion with a margin of error of 2.5%?

A.	1,537
B.	1,290
C.	323
D.	1,291
E.	1,536

anonymous · Answer

@SithsAndGiggles, do you know how to solve this one?