1. The problem statement, all variables and given/known data A candidate wishes to estimate the proportion, among likely voters who would vote for her on election day, with 80% margin of error less than 0.03. What sample size should she use? Answer: 456 2. Relevant equations +/- Z[phat*qhat/sqrt(n)], Z = 1.28, phat = 0.5, qhat = 0.5 3. The attempt at a solution 0.03 = 1.28 sqrt[0.5*0.5/n] 0.03/1.28 = 0.5/sqrt(n) 0.0234 = 0.5/sqrt(n) n = [0.5/0.0234]^2 n = 456 Is the above correct. It matches with the answer 456. I don't know how to delete this question.