A researcher wishes to estimate the proportion of adults who have high-speed Internet access. What size sample should be obtained if she wishes the estimate to be within 0.03 with 90% confidence if (a) she uses a previous estimate of 0.46? b) she does not use any prior estimates? - X Table of critical values Level of Confidence, Area in Each Tail, 5 Critical Value, Z (1 - a) - 100% 90% 0.05 1.645 95% 0.025 1.96 99% 0.005 2.575 Print Done