1. In sample surveys, what is meant by bias? (A) A systematic error in sampling method that leads to an unrepresentative sample (B) Prejudice, for example in ethnic and gender related studies. (C) Natural variability seen between samples (D) Tendency for some distributions to be skewed. (E) Tendency for some distributions to vary from normality. 2. Sampling error is (A) The mean of the sampling statistic. (B) The standard deviation of a sample statistic. (C) The standard error of a sample statistic. (D) The result of bias (E) The difference between a population parameter and an estimate of that parameter. 3. A human resources department plans to survey 100 of the 3,000 employees in the firm. An alphabetical list of the employees is available, a random number between 1 and 30 is picked, and the sample consists of the person that far down the list together with every 30th person after that. This procedure is an example of which type of sampling? A. Cluster B Convenience C. Simple random D. Stratified E. Systematic 4. Before taking an exam, students either went to bed at their normal times or were sleep deprived for 4 or 8 hours. Half of each group were given a caffeine pill before taking the exam. Determine the number of factors, levels for each, and number of treatments. (factor means variable) (A) One factor with two level, five treatments (B) Two factors, one with one and one with two levels, three treatments (C) Two factors, one with two and one with three levels, five treatments (D) Two factors, one with two and one with three levels, six treatments (E) Three factors, each with two levels, six treatments 5. What is bias in conducting surveys? (A) An example of sampling error (B) Lack of a control group (C) Confounding variables (D) Difficulty in concluding cause and effect (E) A tendency to favor the selection of certain members of a population. 6. A botanist is running an experiment on two fertilizers that require different amounts of watering. She has 40 test plots, half of which are in sunny locations, and half are in the shade. She randomly selects 10 sunny plots and 10 shady plots for which to use one fertilizer with its appropriate watering, while the remaining plots are for the other fertilizer with its appropriate watering. Of the following, which is the most important observation about this procedure? (A) The variables, fertilizer and water, are confounded. (B) The variables, fertilizer and sun, are confounded. (C) The variables, water and sun, are confounded. (D) No variables are confounded. (E) There is a hidden lurking variable. 7. A television network conducts a weekly survey to determine the proportion of viewers who watch various programs. For the coming year, they decide to double the sample size. The main benefit of (A) Reduce undercoverage bias. (B) Reduce nonresponse bias. (C) Eliminate sampling error. (D) Decrease population variability. (E) Decrease the standard deviation of the sampling distribution. 8. Which of the following statements is incorrect? (A) Voluntary response samples often underrepresent people with strong opinions. (B) Convenience samples often lead to undercoverage bias. (C) Questionnaires with non-neutral wording are likely to have response bias. (D) There is no way to fix the results if a biased sampling method was employed. (E) Nonresponse bias should be avoided because those who do not respond might have different views from those who do respond. 9. Each of the 30 major league baseball teams carries a 40 person roster. A sample of 60 players (5 percent of all 1,200 players) is to be randomly selected to undergo drug tests. To do this, each team is instructed to put their 40 names in a hat and randomly draw two names. Will this method result in a simple random sample of the 1,200 baseball players? (A) Yes, because each player has the same chance of being selected. (B) Yes, because each team is equally represented. (C) Yes, because this is an example of stratified sampling, which is a special case of simple random sampling. (D) No, because the teams are not chosen randomly. (E) No, because not each group of 60 players has the same chance of being selected. 10. Which of the following is most useful in establishing cause-and-effect relationships? A. A complete census B. A least square regression line showing high correlation C. A simple random sample (SRS) D. A well-designed, well conducted survey incorporating chance to ensure a representative sample E. A controlled experiment 11. A town has one high-school, which buses students from urban, suburban, and rural communities. Which of the following sampling techniques is most recommended in studying attitudes toward military enlistment after high school graduation? (A) Cluster sample (B) Simple random sampletar (C) Stratified sample (D) Systematic sample (E) Voluntary response sample