Researchers Penninx et al. (Archives of General Psychiatry, 2001) looked at the relationship between depression and a person’s ability to survive cardiac disease. The researchers identified 450 men and women with cardiac disease, evaluated them for depression, and followed them for four years. In those four years, of the 89 patients diagnosed with minor or major depression, 26 died of cardiac disease. Of the 361 patients with no diagnosis of depression, 67 died of cardiac disease.
a. Define (in words) the parameters of interest of this study. Also, assign symbols to the parameters. b. State the appropriate null and alternative hypotheses in words.
c. State the appropriate null and alternative hypotheses in symbols.
d. Explain why it is valid to use the theory-based approach to test the hypotheses stated above.
e. Use an appropriate applet to find a theory-based p-value to test the above hypotheses. Report the standardized statistic as well as the p-value.
f. Use an appropriate applet to find a theory-based 95% confidence interval and interpret the resulting interval in the context of the study.
g. Based on your findings, state a complete conclusion about the study. Be sure to address significance, estimation (confidence interval), causation, and generalization.