1. Travelers are asked how many hours they are willing to drive while on vacation in one day. A total of 86 travelers reported a mean of 11.55 hours with a standard deviation of 1.2 hours. Find the 99% confidence interval for the mean number of hours travelers are willing to drive.
What is your value for E?
What is your confidence interval?
2. 18% of the students at Brockport College live in within five miles of the campus. You take a sample of 84 students. What is the 85% confidence interval for the population proportion of students who live within five miles of the campus?
What is your value for E?
What is your confidence interval?
3. A soccer ball manufacturer wants to estimate the mean circumferance of mini-soccer balls withing 0.15 inch. Determine the minimum sample size needed to construct a 99% confidence interval for the population mean. Assume that the population standard deviation is 0.20 inch.