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Define the following terms:

(a) Population

(b) Sample

In Exercises 1.7-1.12, classify each of the studies as either descriptive or inferential. Explain your answers.

Drug Use. The U.S. Substance Abuse and Mental Health Services Administration collects and publishes data on nonmedical drug use, by type of drug and age group, in National Survey on Drug Use and Health. The following table provides data for the years 2003 and 2008. The percentages shown are estimates for the entire nation based on information obtained from a sample (NA, not available).

In Exercises 1.7-1.12, classify each of the studies as either descriptive or inferential. Explain your answers.

Dow Jones Industrial Averages. From the Stock Performance Guide, published online by Istockl on the website 1Stock1.com, we found the closing values of the Dow Jones Industrial Averages as of the end of December for the years 2004 through 2013.

In Exercises 1.7-1.12, classify each of the studies as either descriptive or inferential. Explain your answers.

In-Demand College Majors. In a June 2013 article, published online by The Street, B. O'Connell discussed the results of a survey on opportunities for graduating college students. In one aspect of the survey, the following percentage estimates were reported on which college majors were in demand among U.S. firms. [SOURCE: "The Most In-Demand College Majors This Year." Published by Career-Builder, LLC, 2013.]

Thoughts on Evolution. In an article titled "Who has designs on your student's minds?" (Nature, Vol. 434, pp. 1062-1065), author G. Brumfiel postulated that support for Darwinism increases with level of education. The following table provides percentages of U.S. adults, by educational level, who believe that evolution is a scientific theory well supported by evidence.

(a) Do you think that this study is descriptive or inferential? Explain your answer.

(b) If, in fact, the study is inferential, identify the sample and population.

Big-Banks Break-up. A nationwide survey of 1000 U.S. adults, conducted in March 2013 by Rasmussen Reports (field work by Pulse Opinion Research, LLC), found that 50% of respondents favored a plan to break up the 12 megabanks, which then controlled about 69% of the banking industry.

(a) Identify the population and sample for this study.

(b) Is the percentage provided a descriptive statistic or an inferential statistic? Explain your answer.

In Exercises 1.17-1.22, state whether the investigation in question is an observational study or a designed experiment. Justify your answer each case.

The Salk Vaccine. In the 1940s and early 1950s, the public greatly concerned about polio. In an attempt to prevent this disease, Jonas Salk of the University of Pittsburgh developed a polio vaccine. In a test of the vaccine's efficacy, involving nearly million grade-school children, half of the children received the Salk vaccine; the other half received a placebo, in this case, an injection of salt dissolved in water. Neither the children nor the doctors performing the diagnoses knew which children belonged to which group, but an evaluation center did. The center found that the incidence of polio was far less among the children inoculated with the Salk vaccine. From that information, the researchers concluded that the vaccine would be effective in preventing polio for all U.S. school children; consequently, it was made available for general use.

In Exercises 1.17-1.22, state whether the investigation in question is an observational study or a designed experiment. Justify your answer in each case.

Do Left-Handers Die Earlier? According to a study published in the Journal of the American Public Health Association, left-handed people do not die at an earlier age than right-handed people, contrary to the conclusion of a highly publicized report done 2 years earlier. The investigation involved a 6-year study of 3800 people in East Boston older than age 65. Researchers at Harvard University and the National Institute of Aging found that the "lefties" and "righties" died at exactly the same rate. "There was no difference, period," said Dr. J. Guralnik, an epidemiologist at the institute and one of the coauthors of the report.

In Exercises 1.17-1.22, state whether the investigation in question is an observational study or a designed experiment. Justify your answer in each case.

Heart Failure. In the paper "Cardiac-Resynchronization Therapy with or without an Implantable Defibrillator in Advanced Chronic Heart Failure" (New England Journal of Medicine, Vol. 350, pp. 2140-2150), M. Bristow et al. reported the results of a study of methods for treating patients who had advanced heart failure due to ischemic or nonischemic cardiomyopathies. A total of 1520 patients were randomly assigned in a 1:2:2 ratio to receive optimal pharmacologic therapy alone or in combination with either a pacemaker or a pacemaker-defibrillator combination. The patients were then observed until they died or were hospitalized for any cause.

Ballistic Fingerprinting. In an on-line press release, ABCNews.com reported that "...73 percent of Americans... favor a law that would require every gun sold in the United States to be test-fired first, so law enforcement would have its fingerprint in case it were ever used in a crime."

(a). Do you think that the statement in the press release is inferential or descriptive? Can you be sure?

(b). Actually, ABCNews.com conducted a telephone survey of a random national sample of 1032 adults and determined that 73% of them favored a law that would require every gun sold in the United States to be test-fired first, so law enforcement would have its fingerprint in case it were ever used in a crime. How would you rephrase the statement in the press release to make clear that it is a descriptive statement? an inferential statement?