Exam 12: Relationships Between Categorical Variables

Suppose you hear a report that says the chances of developing lung cancer increase by 10 times, just by living in the city versus the country.How do you interpret this?

For Questions , use the following narrative Narrative: Audition qualifications Suppose an audition process requires applicants to first meet a series of qualifications before they can be accepted for an audition.Suppose 88% of the women met these qualifications, and 86% of the men met these qualifications.Also assume that there were 100 men and 100 women who applied. -{Audition qualifications narrative} What is the odds ratio for being accepted (versus rejected) for women compared to men?

Suppose you are on a jury in a trial someday.How could you encounter Simpson's Paradox?

For Questions use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} What is the odds ratio of developing polyps for colon cancer patients who don't take an aspirin a day versus those that do?

For Questions , use the following narrative Narrative: Genetic defect Suppose a population contains 100,000 individuals, of which 500 are carriers of a certain genetic defect. -{Genetic defect narrative}Which of the following is an appropriate way to express this result in terms of odds?

For Questions , use the following narrative Narrative: Audition qualifications Suppose an audition process requires applicants to first meet a series of qualifications before they can be accepted for an audition.Suppose 88% of the women met these qualifications, and 86% of the men met these qualifications.Also assume that there were 100 men and 100 women who applied. -{Audition qualifications narrative} What is the selection ratio for men compared to women? Interpret your answer.

For Questions , use the following narrative Narrative: Audition qualifications Suppose an audition process requires applicants to first meet a series of qualifications before they can be accepted for an audition.Suppose 88% of the women met these qualifications, and 86% of the men met these qualifications.Also assume that there were 100 men and 100 women who applied. -{Audition qualifications narrative} What is the odds ratio for being accepted (versus rejected) for men compared to women?

Simpson's Paradox makes it clear that it is dangerous to __________ information across groups, especially if the subjects or experimental units were not __________ assigned to those groups.

For Questions , use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} How many cells will the contingency table have for the data presented by this study?

For Questions , use the following narrative Narrative: Talent and gender Suppose a talent contest is looking for people who can either sing or act.900 people tried out for the first round of auditions, 300 women and 600 men.Of the men who tried out, 55% of them were allowed to go on to the next round, compared to 42% of the women.However, if you break the data down by singing versus acting auditions, the relationship changes.For acting, 20% of the women made it through, compared to 15% of the men; for singing, 85% of the women made it through, compared to 75% of the men. -{Talent and gender narrative}What is the statistical phenomena that occurred in this situation?

For Questions , use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} Make a contingency table summarizing the data from this study, making the explanatory variable the row variable and the response variable the column variable.

For Questions , use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} For colon cancer patients who take an aspirin a day, what is the expected rate for developing subsequent polyps?

What does Simpson's Paradox teach us?

When you see a group of individuals summarized into a single contingency table containing only one row variable and one column variable, what should your reaction be?

For Questions , use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} Does taking aspirin appear to be related to the chance of developing subsequent polyps in colon cancer patients? Justify your answer using percentages.

For Questions use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} What is the increased risk of developing polyps for colon cancer patients who don't take an aspirin a day? Interpret your answer.

For Questions , use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} What percentage of patients on the placebo did not develop subsequent polyps?

For Questions use the following narrative Narrative: Aspirin and polyps A study done by the Ohio State University Medical Center examined whether or not taking an aspirin a day would help colon cancer patients reduce the chance of getting subsequent colon polyps.635 patients with colon cancer participated; 317 of them were randomly assigned to the aspirin group, and the other 318 patients were assigned to a placebo (non-aspirin) group.54 patients in the aspirin group developed subsequent polyps, compared to 86 patients in the non-aspirin group.Many confounding variables were controlled for in this well-designed randomized experiment. -{Aspirin and polyps narrative} What are the odds of developing subsequent polyps for colon cancer patients who don't take an aspirin a day?

For Questions , use the following narrative Narrative: Blood clot risk Suppose you hear on the news that sitting on an airplane for five hours or more without getting up and walking around increases your chances of developing blood clots by 10 times. -{Blood clot risk narrative} The timeline for the risk is not given.Explain what that means in terms of what conclusions you can make about the results.

For Questions , use the following narrative Narrative: Blood clot risk Suppose you hear on the news that sitting on an airplane for five hours or more without getting up and walking around increases your chances of developing blood clots by 10 times. -{Blood clot risk narrative} Does this increased risk apply to anyone and everyone? Explain why or why not.