STAT 330 Quiz 20 12102/2011 NAME and NAID _________________________ Choose the correct answer to each question from the list below. ______1. A motorist claims that the Fargo Police issue an average of 60 speeding tickets per day. A random sample of 100 days showed an average of 65 tickets issued with a standard deviation of 10. Which test should be used? ______2. The average SAT score in mathematics is 483. A special preparation course states that it can increase scores. A sample of 16 students completed the course, and the average of their scores was 494 with a standard deviation of 100. Which test should be used? ______3. A recent study claimed that at least 15% of all eighthgrade students are overweight. In a sample of 80 students 9 were found to be overweight. Which test should be used? ______4. A medical researcher wishes to see whether the average pulse rate of smokers is higher than the average pulse rates of nonsmokers. Samples of 100 smokers and 100 nonsmokers are selected. Which test should be used? ______5. A researcher suggests that male nurses earn more than female nurses. A survey of 16 male nurses had a mean of $23,800 with a standard deviation of $300. A survey of 20 female nurses had a mean of $23,750 with a standard deviation of $250. Which test should be used? ______6. In problem 5 the pvalue = 0.0156. If = 0.05 then what is the correct decision? ______7. A professional bowler has been having trouble \"hitting the pocket\" in order to get strikes. His average has been 205 with a standard deviation of 10. If in his next 15 games, his standard deviation is 14, test his hypothesis that his game is more variable than in the past. At alpha =0.05 which test should be used? ______8. A chewing gum manufacturer wishes to determine if his customers prefer one flavor of gum to another flavor. He selects a random sample of customers and records the flavor of gum that is purchased. The flavors chosen were Spearmint, Wintergreen, Cherry, and Cinnamon. Which test should be used to see if each flavor is equally preferred? A. Ztest for a single mean C. Ttest for a single mean E. ZTest for a single proportion G. ChiSquare test for the variance I. Reject Ho B. Ztest for the difference of two means D. Ttest for the difference of two means F. ZTest for the difference of two proportions H. Chisquare test for goodness of fit J. Do not reject Ho