1. Find critical values(round to 3 decimal places) for the following confidence intervals and distributions. Include a sketch for each. a) 90% confidence interval for a normal distribution. b) 92% confidence interval for a t-distribution with df = 16. c) 95% confidence interval for a chi-square distribution with df = 7.

2. The Forest Service took a random sample of Yellowstone Park visitors and asked if they favor restrictions on the number of vehicles allowed to enter the park: 89 of 150 say yes. a) Give a 95% confidence interval for the proportion of all Yellowstone visitors who favor the restrictions. Include the sample proportion, and the Margin of Error. Express the confidence interval in a sentence. b) Are you 95% confident that more than half are in favor? Explain. c) What sample size would be needed to obtain a margin of error of 4%.