Statistics Exam: Hypothesis Testing and Confidence Intervals - Prof. B. Bare, Exams of Probability and Statistics

Download Statistics Exam: Hypothesis Testing and Confidence Intervals - Prof. B. Bare and more Exams Probability and Statistics in PDF only on Docsity! Test Four Q SCI 381 Dr. Bare Name: ________________________ Hourly Examination Four Closed book. May use calculator and formula card. Show all work for full credit. This means show which formula is used; plug in a few representative data points to demonstrate that you know how to use the formula; provide the correct numerical answer. (100 points) NOTE: FOR ALL PROBLEMS PROVIDE A MATHEMATICAL STATEMENT OF YOUR NULL AND ALTERNATIVE HYPOTHESIS; PROVIDE THE TEST STATISTIC AND THE CRITICAL VALUE(S); MAKE A DECISION;STATE YOUR CONCLUSION IN WORDS (i.e., FIVE PARTS). (20) 1. The Big Time Brewery sells beer in bottles labeled 32 ounces. A local consumer advocate group thinks that the brewery is cheating its customers. The group randomly selects 49 bottles and accurately measures their contents. They determine that the sample mean fill is 31.7 ounces with a sample standard deviation of 0.70 ounce. Let  = .01 and test the group’s claim that the mean fill level is less than 32 ounces. Determine the P-value for this test. Test Four (20) 2. Metro claims that the mean waiting time for a bus during rush hour in Seattle is less than 10 minutes and is normally distributed. A random sample of 20 waiting times produces a mean wait of 8.5 minutes and a sample standard deviation of 2.1 minutes. At  = .05, test Metro’s claim. 2