1. A random sample of 26 offshore oil workers took part in a simulated escape exercise, and their times (sec) to complete the escape are recorded. The sample mean is 370.69 sec and the sample standard deviation is 24.36 sec. Construct a 95% confidence interval on the true average escape time. Interpret your interval.
2. A study is to be conducted on the proportion of homeowners who own at least two TV sets. How large a sample is required if we wish to be 90% confident that the error in estimating this quantity is within 1.5%?
3. An investigator wishes to estimate the difference between population mean SAT-M scores of incoming freshmen in the College of Engineering and in the College of Science at Purdue University. The population standard deviations are both roughly 100 points and equal sample sizes are to be selected. What value of the common sample size n will be necessary to estimate the difference to within 10 points with 99% confidence?