2. 1. A university planner wants to determine the proportion of spring semester students who will attend summer school. She surveys 32 current students discovering that 12 will return for summer school. Construct a 90% confidence interval estimate for the proportion of current spring students who will return for summer school.

3. 1. A health club annually surveys its members. Last year, 33% of the members said they use the treadmill at least 4 times a week. How large of sample should be taken this year to estimate the percentage of members who use the treadmill at least 4 times a week? The estimate is desired to have a margin of error of 5% with a 95% level of confidence.