1. The administrator of the only hospital in a community of 150,000 people notices that many patients admitted for salmonella infection indicate that they drink unpasteurized milk from a local dairy. Periodic inspections by the state health department sometimes find milk samples contaminated with salmonella organisms. The dairy has resisted pasteurizing the milk because the state inspections do not always indicate salmonella contamination. The hospital administrator decides to conduct a hospitalbased study that may show association between unpasteurized milk consumption and salmonella cases in the community. The following information is abstracted from hospital medical records. (30 points)
   • During the past three years, 10% of the community population was hospitalized at least one day
   • A review of admission forms indicated that of 15,000 admitted patients, 64 cases admitted for salmonella infections
   • A total of 3,487 of the 15,000 admitted patients reported that they had consumed unpasteurized milk
   • Thirteen of the patients who reported that they had consumed unpasteurized milk were admitted for salmonella infections
   1. a) What study design should the hospital administrator select? Why?
   2. b) Calculate the appropriate measure of association
   3. c) What can be concluded from this hospitalbased study with respect to the association of consuming unpasteurized milk and salmonella infection?