According to a new study released by Infosys, a global leader in consulting, outsourcing and technology, more than three quarters (77%) of U.S. consumers say that banking on their mobile device is convenient. (Data extracted from "Infosys Survey Finds Mobile Banking Customers Love Ease and Convenience, Yet Reliability and Security Concerns Remain," PR Newswire, 2012, bit.ly/Ip9RUF.)
a. If you conduct a follow up study to estimate the population proportion of U.S. consumers who say that banking on their mobile device is convenient, would you use a TT of 0.77 or 0.50 in the sample size formula?
b. Using you answer in part (a), find the sample size necessary to estimate, with 95% confidence, the population proportion to within ±0.03.