1. A researcher wishes to estimate with 90% confidence, the proportion of adults who have high-speed Internet access. He estimate must be accurate within 5% of the true proportion.
a) What is the minimum sample size needed using a prior study that found that 48% of the respondents said they have high-speed Internet access? (Round to nearest whole number.)
b) What is the minimum sample size needed assuming that no preliminary estimate is available?
(Round to the nearest whole number.)