Question: Identify the sample for the given problem. Choose the correct answer below.
Answer Choices: a. The 992 American men surveyed by telephone b. All American men c. Half of all American men d. Some of the 992 American men surveyed by telephone
Answer: a. The 992 American men surveyed by telephone
Question: Identify the population parameter in the given study. Choose the correct answer below.
Answer Choices: a. The total number of all American men b. The mean threat rating of all American men on Iran’s nuclear program c. The mean threat rating on Iran’s nuclear program of the 992 American men surveyed by telephone d. The number of American men selected
Answer: b. The mean threat rating of all American men on Iran’s nuclear program
Question: Identify the sample statistic. Choose the correct answer below.
Answer Choices: a. The total number of American men b. The mean threat rating of all American men on Iran’s nuclear program c. The mean threat rating on Iran’s nuclear program of the 992 American men surveyed by telephone d. The number of American men selected
Answer: c. The mean threat rating on Iran’s nuclear program of the 992 American men surveyed by telephone
Question: In a poll, 1,004 women in a country were asked whether they favor or oppose the use of “federal tax dollars to fund medical research using stem cells obtained from human embryos.” Among the respondents, 47% said that they were in favor. Describe the statistical study. What is the population in the given problem? Choose the correct answer below.
Answer Choices: A. All women in the country B. 47% of the 1,004 women selected C. 47% of all women in the country D. The 1,004 women selected
Answer: A. All women in the country
Question: Identify the sample for the given problem. Choose the correct answer below.
Answer Choices: A. 47% of all women in the country B. The 1,004 women selected C. All women in the country D. 47% of the 1,004 women selected
Answer: B. The 1,004 women selected
Question: What is the population parameter in the given study? Choose the correct answer below.
Answer Choices: A. The percentage of all women in the country who say that they are in favor B. The total number of all women in the country C. The percentage of the 1,004 women selected who say that they are in favor D. The number of women selected
Answer: A. The percentage of all women in the country who say that they are in favor
Question: Identify the sample statistic. Choose the correct answer below.
Answer Choices: A. 47% B. The total number of all women in the country C. 1,004 D. 53%
Answer: A. 47%
Question: A researcher wants to determine the average given below. Describe how the researcher should apply the five basic steps in a statistical study. (Assume that all the people in the poll answered truthfully.) The average number of college students per college that study all night before an exam. Determine how to apply the first basic step in a statistical study in this situation. Choose the correct answer below.
Answer Choices: A. The population is all colleges. The researcher wants to estimate the average number of college students per college that do not study all night before an exam. B. The population is all college students that study all night before an exam. The researcher wants to estimate the average number of college students per college that study all night before an exam. C. The population is all colleges. The researcher wants to estimate the average number of college students per college that study all night before an exam. D. The population is all college students that study all night before an exam. The researcher wants to estimate the average number of college students per college that do not study all night before an exam.
Answer: C. The population is all colleges. The researcher wants to estimate the average number of college students per college that study all night before an exam.
Question: Determine how to apply the second basic step in a statistical study in this situation. Choose the correct answer below.
Answer Choices: A. The researcher should only gather raw data from college students that study all night before an exam. B. The researcher should only gather raw data from college students that do not study. C. The researcher should gather data about study habits from the largest sample of college students about whom the researcher can gather data. D. The researcher should gather raw data from all college students.
Answer: C. The researcher should gather data about study habits from the largest sample of college students about whom the researcher can gather data.
Question: Determine how to apply the third basic step in a statistical study in this situation. Choose the correct answer below.
Answer Choices: A. The sample statistic of interest is the average number of college students per college that study all night before an exam. B. The sample statistic of interest is the percentage of college students that do not study all night before an exam. C. The sample statistic of interest is the percentage of college students that study all night before an exam. D. The sample statistic of interest is the average number of college students per college that do not study all night before an exam.
Answer: A. The sample statistic of interest is the average number of college students per college that study all night before an exam.
Question: Determine how to apply the fourth basic step in a statistical study in this situation. Choose the correct answer below.
Answer Choices: A. If the percentage of college students that study all night before an exam in the sample is greater than 50%, then the researcher can be confident that all college students study all night before an exam. B. If the researcher followed correct procedures, he or she can be confident that the sample statistic is equal to the average number of college students that study all night before an exam. C. The researcher should use the sample statistic as an estimate for the population value of the average number of college students that study all night before an exam and then use the methods of statistics to determine how good that estimate is. D. The sample statistic provides no useful information to the researcher in this situation.
Answer: C. The researcher should use the sample statistic as an estimate for the population value of the average number of college students that study all night before an exam and then use the methods of statistics to determine how good that estimate is.
Question: Determine how to apply the fifth basic step in a statistical study in this situation. Choose the correct answer below.
Answer Choices: A. The researcher cannot draw any conclusions based on the value of the sample statistic. B. The researcher knows that the sample statistic is equal to the population parameter, so he or she may draw conclusions with complete confidence.
Answer: A. The researcher cannot draw any conclusions based on the value of the sample statistic.
Question: A researcher wants to determine the average given below. Describe how the researcher should apply the five basic steps in a statistical study. (Assume that all the people in the poll answered truthfully.) The average time to failure of batteries in a particular model of digital watch.
Answer Choices: Step 1: A. The population is all digital watches of this model whose batteries last longer than average. B. The population is all digital watches not of this model. C. The population is all digital watches of this model whose batteries do not last longer than average. D. The population is all digital watches of this model.
Answer: D. The population is all digital watches of this model.
Question: To determine her blood sugar level, Keri divides up her day into three parts: morning, afternoon, and evening. She then measures her blood sugar level at 2 randomly selected times during each part of the day. What type of sampling is used?
Answer Choices: A. Systematic sampling B. Convenience sampling C. Simple random sampling D. Stratified sampling
Answer: D. Stratified sampling
Question: Consider the statistical study below and then a. identify the population and the population parameter of interest, b. describe the sample and sample statistic for the study, and c. identify the type of study. 106 people with a household larger than five people were given cognitive tests. It was discovered that those participants who were given a suggestion their household size might affect their performance on the test actually did worse on the test. a. Identify the population and the population parameter of interest. Choose the correct answer below.
Answer Choices: A. The population is all people with households larger than five people; population parameters are test scores for the 106 people studied, categorized by whether or not each individual was given a suggestion. B. The population is the 106 people studied; population parameters are test scores for all people, categorized by whether or not each individual was given a suggestion. C. The population is all people with households larger than five people; population parameters are test scores for all people, categorized by whether or not each individual was given a suggestion. D. The population is the 106 people studied; population parameters are test scores for the 106 people studied, categorized by whether or not each individual was given a suggestion.
Answer: C. The population is all people with households larger than five people; population parameters are test scores for all people, categorized by whether or not each individual was given a suggestion. b. Describe the sample and sample statistic for the study. Choose the correct answer below. Answer Options: A. The sample is the 106 people studied; the sample statistic is the test scores for all people, categorized by whether or not each individual was given a suggestion. B. The sample is the 106 people studied; the sample statistic is the test scores for the 106 people studied, categorized by whether or not each individual was given a suggestion. C. The sample is all people with households larger than five people; the sample statistic is the test scores for all people, categorized by whether or not each individual was given a suggestion. D. The sample is all people with households larger than five people; the sample statistic is the test scores for the 106 people studied, categorized by whether or not each individual was given a suggestion. Correct Answer: B. The sample is the 106 people studied; the sample statistic is the test scores for the 106 people studied, categorized by whether or not each individual was given a suggestion. c. Identify the type of study. Choose the correct answer below. Answer Options: A. Random sample B. Observation C. Single blind D. Experiment Correct Answer: D. Experiment
Question: Identify any potential sources of bias in the following study. From a poll of people who recently bought cold medicine at all stores of a large drugstore chain, investigators concluded that the mean time between colds for all Americans is 5.6 months. What sources of bias, if any, might this study have?
Answer Choices: A. Both selection and participation bias B. Selection bias only C. Participation bias only D. There is probably no bias in the study.
Answer: A. Both selection and participation bias
Question: Identify any potential sources of bias in the following study. In order to determine the opinions of people in the 18- to 27-year age group on controlling illegal immigration, researchers survey 2500 National Guard members in this age group. What sources of bias, if any, might this study have?
Answer Choices: A. Participation bias only B. Selection and participation bias C. Selection bias only D. There is probably no bias in the study.
Answer: B. Selection and participation bias
Question: The headline “Drugs shown in 98 percent of movies” accompanied a news story that described a “government study” claiming that drug use, drinking, or smoking was depicted in 98% of the top movie rentals. Discuss whether the headline accurately represents the story.
Answer Choices: A. The headline refers to drugs whereas the story refers to “drug use, drinking, or smoking.” The headline is very misleading because the term “drugs” is generally considered to consist of drugs other than cigarettes or alcohol. Also, all movies consist of more than just the top movie rentals. B. The headline is downplaying the results presented in the story, because the government produced the study. C. The headline is exaggerating the results given in the story. The headline uses a bigger figure for the amount of drugs in movies than the figure given in the story. D. The headline appears to accurately represent the news story.
Answer: A. The headline refers to drugs whereas the story refers to “drug use, drinking, or smoking.” The headline is very misleading because the term “drugs” is generally considered to consist of drugs other than cigarettes or alcohol. Also, all movies consist of more than just the top movie rentals.
Question: Discuss the differences between the following questions, each of which could be the basis for a statistical study. What percentage of Internet dates lead to marriage? What percentage of marriages begin with Internet dates?
Answer Choices: A. The percentage of marriages beginning with Internet dates can be accurately measured while the percentage of Internet dates that lead to marriage cannot be accurately measured. B. The questions are too different to compare. C. The questions have different populations. D. The percentage of marriages beginning with Internet dates would be an observation while the percentage of Internet dates that lead to marriage would be an experiment.
Answer: C. The questions have different populations.
Question: 14. Testing whether the slope of the population regression line could be zero is equivalent to testing whether the population ________ could be zero.
Answer Choices: a. standard error of estimate b. prediction interval c. y-intercept d. coefficient of correlation
Answer: d. coefficient of correlation
Question: 15. A multiple regression equation includes 4 independent variables, and the coefficient of multiple determination is 0.64. How much of the variation in y is explained by the regression equation?
Answer Choices: a. 80% b. 16% c. 32% d. 64%
Answer: d. 64%