In this exercise we investigate the effect of gender on the odds of getting a high GPA.
(a) Use gender to predict HIGPA using a logistic regression. Summarize the results.
(b) Perform a logistic regression using gender and the two SAT scores to predict HIGPA. Summarize the results.
(c) Compare the results of parts (a) and (b) with respect to how gender relates to HIGPA. Summarize your conclusions.
Died 63 16
Survived 2037 784
Total 2100 800
And here are the more detailed data where the patients are categorized as being in good condition or poor condition:
Good condition Hospital A Hospital B
Died 6 8
Survived 594 592
Total 600 600
Poor condition Hospital A Hospital B
Died 57 8
Survived 1443 192
Total 1500 200
(a) Use a logistic regression to model the odds of death with hospital as the explanatory variable. Summarize the results of your analysis and give a 95% con?dence interval for the odds ratio of Hospital A relative to Hospital B.
(b) Rerun your analysis in (a) using hospital and the condition of the patient as explanatory variables. Summarize the results of your analysis and give a 95% con?dence interval for the odds ratio of Hospital A relative to Hospital B.
(c) Explain Simpson's paradox in terms of your results in parts (a) and (b).