Question

Use the following information for questions 25-26. Show your calculations and reasoning to the right side of the question, then select one answer Food-specific Attack Rates of Gastroenteritis Persons Eating Food Item Persons Not Eating Food Item Food Item potato salad hamburger baked beans Total ML Attack Rate(%) 100 88 126 90 99 76 55 34 Totall Attack Rate (%) 33 5 3116 10 S 71 48 milk 25. The attack rate for those persons who ate baked beans is a. 88.0 % b. 76.8 % c. 71.4% d. 50.0 % 26. Based on the information above, which of the following food items is most likely to be infective? Show your reasoning, then select one answer. a. baked beans b. milk c. potato salad d. hamburger Use the following information for questions 27-29. Show your calculations to the right side of the question, then select one answer. Audiometric tests were given to 500 persons with suspected hearing problems, of whom 300 were actually found to have them. The results were as follows: Hearing Problems Audiometric Test Result Present Absent 270 Negative 140 27. The specificity of the audiometric test is a. 60% b. 70% c. 80% d. none of the above 28. The sensitivity of the audiometric test is a. 60% b. 70% c. 80% d. none of the above

Answer 1

25. A food-specific attack rate is the number of persons who ate a specified food and became ill divided by the total number of persons who ate that food

76/99 *100=76.8%
26. Potato salad seems infective as majority have developed illness among those who have eaten and very less number of illness in those who have not eaten .

27. Specificity is fraction of those without disease who will have a negative test result

140/200*100

70%

28. sensitivity is fraction of those with disease who have positive test result

270/300*100 90%
so the answer is none of above