Q1. In a recent study of 154 households, 54 had air conditioning. Find the 95% confidence interval of the true proportion who have air conditioning.
Q2. Mr. Hoyack, and Dr. Jensen wish to estimate, within 0.05%, the true proportion of Cochise College students who study at least 3 hours each school night and they want to be 99% confident.
a) How large a sample is necessary if a study two years ago showed that 65% of 450 students studied at least 3 hours each school night?
b) If no estimate of the sample proportion is available, how large should the sample be?