Exam 27: Putting What You Have Learned to the Test

CASE STUDY 27.10 CHILL OUT-MOVE TO HONOLULU For Questions , use the following narrative Narrative: Case study 27.10 summary This study was based on a poll that measured citizens' hostility levels and compared them with their cities' death rates.The research findings were reporting as the following: 1) people with higher hostility levels have higher rates of heart disease deaths and overall deaths; 2) cities with higher hostility scores consistently had higher death rates; 3) cities with lower hostility scores had lower death rates.The results were summarized by saying "Hostile cities may want to chill out." The study was based on 10 cities, one from each of the states with the five highest and five lowest heart disease death rates.Philadelphia had the highest levels of both (hostility and death rate), and Honolulu had the lowest levels of both (hostility and death rate).It was reported that statistically, the probability of the observed correlation between hostility and death rate occurring by chance is less than 1 in 10,000. -{Case study 27.10 narrative} The main implication by the researchers (and the media) about the results of this study is that if cities like Philadelphia would lower their hostility index, they would also lower their death rates.Is that a valid conclusion? Explain why or why not.

CASE STUDY 27.3 CHILDREN ON THE GO For Questions , use the following narrative Narrative: Case study 27.3 summary The researchers of this study concluded that children who move often are 35 percent more likely to fail a grade and 77 percent more likely to have behavioral problems than children whose families move rarely.These results were based on a nationwide study of 9,915 youngsters aged 6-17."High movers" were defined as those who had moved at least 6 times.High movers were 1.35 times more likely to have failed a grade and 1.77 times more likely to have developed at least four frequent behavioral problems (ranging from depression to impulsiveness to destructiveness).The results were adjusted for poverty, single parenting, belonging to a racial minority, and having parents with less than a high school education. -{Case study 27.3 narrative} This was most likely what type of observational study?

CASE STUDY 27.5 YOU CAN WORK AND GET YOUR EXERCISE AT THE SAME TIME For Questions , use the following narrative Narrative: Case study 27.5 summary One in five clerical workers walks about a quarter mile a day just to complete routine functions like faxing, copying, and filing, a national survey on office efficiency reports.The survey also shows that the average office worker spends close to 15 percent of the day just walking around the office. -{Case study 27.5 narrative} The survey was commissioned by Canon U.S.A., maker of office copiers and printers that claim to cut the time and money "spent running from one machine to the next." In what way might this cause a problem for the results of the study?

CASE STUDY 27.7 UNPALATABLE PATE For Questions , use the following narrative Narrative: Case study 27.7 summary News article excerpt: An exploratory study asked roughly 300 Australian students whether they approved or disapproved of certain uses of animals.Researchers concluded that students frequently condemned consumptive practices while endorsing consumption itself.For example, nearly three-fourths of the students disapproved of "force-feeding geese to make their livers swell up to produce pate for restaurants" but the majority did not disapprove of "eating pate produced by the force-feeding of geese." The authors interpreted these findings as evidence of an inconsistency between people's attitudes and behaviors toward the use of animals. -{Case study 27.7 narrative} It appears that the researchers only offered two choices for answers to their questions: approve or disapprove.What is the impact of this on the results of the survey?

CASE STUDY 27.6 SEX, ALCOHOL, AND THE FIRST DATE For Questions , use the following narrative Narrative: Case study 27.6 summary Young couples are much more likely to have sex on their first date if the male partner drinks alcohol and the woman doesn't, new research shows.The study was based on interviews with 2,052 teenagers.They reported having sex on a first date only 6% of the time if the female drank alcohol while the male did not, compared to 8% of the time when neither partner drank.Nineteen percent of the teens reported having sex when both partners drank, but the highest frequency of sex on the first date - 24 percent - was reported when only the male drank. -{Case study 27.6 narrative} The margin of error for these results is about plus or minus 2%.What real meaning does the margin of error have for this particular study, in terms of making conclusions about the population percentages?

CASE STUDY 27.11 SO YOU THOUGHT HOT DOGS WERE BAD FOR YOU? For Questions , use the following narrative Narrative: Case study 27.11 summary In a magazine article, three research groups reported a link between cured-meat consumption and cancer.Among 232 cases in one study, children who ate 12 or more hot dots in a month were nine times as likely as hot dog-free controls to develop leukemia.Researchers also found an increased risk for kids whose fathers ate a lot of hot dogs.Another study involving 234 cases of various childhood cancers found that children whose mothers ate hot dogs at least once a week were twice as likely as controls to develop brain tumors.The results may be due to the N-nitroso compounds in cured meats, researchers say.However, they warn that the studies are far from conclusive. -{Case study 27.11 narrative} What important statistical information is missing that would have helped to put the 'nine times as likely to develop leukemia' result into proper perspective?