Question: A University of Utah study examined 7,925 severely obese adults who had gastric bypass surgery and an identical number of people who did not have the surgery (The Boston Globe, August 23, 2007). The study wanted to investigate whether losing weight through stomach surgery prolonged the lives of severely obese patients, thereby reducing their deaths from heart disease, cancer, and diabetes. Over the course of the study, 534 of the participants died. Of those who died, the cause of death was classified as either a disease death (disease deaths include heart disease, cancer, and diabetes) or a nondisease death (nondisease deaths include suicide or accident). The following contingency table summarizes the study's findings:
In a report, use the sample information to:
1. Determine at the 5% significance level whether the cause of death depends on the method of losing weight.
2. Discuss how the findings of the statistical test used in question 1 might be used by those in the health industry.