1 F12 STAT 110 Practice EXAM 1 Name__________________________________ Questions 1-3 are based on the following description You want to know the opinions of American teachers about establishing a test for high school graduation. You obtain a list of the members of the National Education Association (the largest teacher’s union) and mail a questionnaire to 2,500 teachers chosen at random from this list. In all, 1,357 teachers mail back completed surveys. 1. The population for this study is A) the 2,500 teachers who received the survey B) the 1,357 teachers who mailed back completed surveys C) all American teachers D) teacher members of the National Education Association 2. The sample for this study is A) the 2,500 teachers who received the survey B) the 1,357 teachers who mailed back completed surveys C) all American teachers D) teacher members of the National Education Association 3. The sampling frame for this study is A) the 2,500 teachers who received the survey B) the 1,357 teachers who mailed back completed surveys C) all American teachers D) teacher members of the National Education Association A list of graduate students for the department of statistics at the University of South Carolina are listed in the following table. 01. Chalmers 02. Chen, H 03. Cheng 04. Chen, Y 05. Clark 06. Du 07. Feng 08. Fu 09. Gao 10. Habinger 11. Hartnett 12. Hill 13. Ishikawa 14. Jang 15. Lauer 16. Lawrence 17. Lewis 18. Li, L 19. Li, T 20. Liu 21. McMahan 22. Moran 23. Peng 24. Rahman 25. Ren 26. Scott 27. Thompson 28. Wanda 29. Wang 30. Wu 31. Yang 4. Use the following list of random digits to find the 5th element for a simple random sample. 28576 10317 03314 67721 09265 A) Lewis B) Wanda C) McMahan D) Yang2 Questions 5-11 are based on the following description A recent poll, conducted February 1-3, asked 1,072 randomly selected adults, “Do you plan on watch all, most, some, or none of the Superbowl this Sunday?” 740 responded they would watch at least part of Superbowl XLV. 5. Find the observed proportion (the sample proportion), p, of those who will watch at least part of the Superbowl XLV. A) , B)  , C)  D) √ , E) √ 6. Find the estimated margin of error for 95% confidence A) , B)  , C)  D) √ , E) √ 7. Suppose the polling company got their sample by standing outside of a football stadium after a game and asking the first 1,072 spectators as they leave the game. What type of sampling scheme would this be? A) Stratified Random Sampling B) Voluntary Response Sample C) Cluster Sample D) Convenience Sample 8. If the polling company wanted to be able to make a statement by gender about who was planning to watch at least some of the Superbowl, they could use a A) Stratified Random Sample B) Voluntary Response Sample C) Cluster Sample D) Convenience Sample 9. In order to reduce bias in this study, the researchers would have to A) reduce the sample size B) increase the sample size C) make sure to have the best random sampling scheme 10. In order to reduce variability of the sample proportion in this study, the researchers would have to A) reduce the sample size B) increase the sample size C) make sure to have the best random sampling scheme 11. Suppose a respondent in this study answered they would watch at least some of the Superbowl only because they thought that is what they are supposed to say, but they were actually not planning to watch it. This study would suffer from a A) Sampling Error: Bad Sampling Method B) Non-Sampling Error: Non-Response Error C) Non-Sampling Error: Response Error D) Non-Sampling Error: Processing Error3 Questions 12-16 are based on the following description There is a long standing controversy surrounding mass vaccination of military personnel with anthrax vaccine. In the 1950’s Brachman Study, workers at four goat hair mills were recruited into a trial of an anthrax vaccine. Several reports of this study claim that the anthrax vaccine studied was effective, since the rate of anthrax was statistically significantly higher in the placebo group. 12. It turns out that randomization was not done properly and that workers in the placebo group had much higher exposure to anthrax spores. So, it cannot be determined whether the higher rate of anthrax in the placebo group was due to the lack of vaccination or the higher exposure to the anthrax spores. The fact that we cannot tell apart the effect of the anthrax exposure and lack of vaccination on contraction of anthrax is called A) confounding B) lurking C) random sampling error D) placebo effect 13. Perhaps a better design for this study would have been to first divide the workers into groups by exposure, maybe a group for high exposure and a group for low exposure according to job duties. Then subjects within each exposure group could be randomly allocated to either the vaccinated or the placebo group. This would be an example of a A) matched pairs design B) completely randomized design C) block design D) simple random sample 14. What does it mean that the rate of anthrax contraction is “statistically significantly higher” for those not vaccinated? The researchers noticed A) anthrax rate so much higher in the unvaccinated group, this would rarely occur by chance B) anthrax rate so much higher in the unvaccinated group, this would never occur by chance C) anthrax rate higher in the unvaccinated group, but may be explained by chance D) everyone in the unvaccinated group contracted anthrax 15. This study is a(n) A) experiment B) observational study C) sample survey 16. What would it mean to say that the rate of anthrax contraction is “not statistically significantly higher” for those not vaccinated? It would mean that the researchers could have noticed A) anthrax rate so much higher in the unvaccinated group, this would rarely occur by chance B) anthrax rate so much higher in the unvaccinated group, this would never occur by chance C) anthrax rate higher in the unvaccinated group, but may be explained by chance D) nobody in the unvaccinated group contracted anthrax4 Questions 17-23 are