Question 189502: A physician's health study of the effectiveness of aspirin in the reduction of heart attacks was begun in 1982 and completed in 1987 (see C. Hennekens et al., "Findings from the Aspirin Component of the Ongoing Physician's Health Study," The New England Journal of Medicine 318 (January 28, 1988): 262-264). Of 11,037 male medical doctors in the United States who took one 325 mg buffered aspirin tablet every other day, 104 suffered heart attacks during the five-year period of the study. Of 11,034 male medical doctors in the United States who took a placebo (i.e., a pill that, unknown to the participants in the study, contained no active ingredients), 189 suffered heart attacks during the five-year period of the study. Is there evidence that the proportion having heart attacks is significantly lower for the male medical doctors in the United States who received the buffered aspirin every other day than for those who received a placebo? Does this lead you to believe that taking one buffered aspirin every other day is effective in reducing the incidence of heart attacks? Explain.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Of 11,037 male medical doctors in the United States who took one 325 mg buffered aspirin tablet every other day, 104 suffered heart attacks during the five-year period of the study.
p(aspirin) = 104/11037 = 0.00942
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Of 11,034 male medical doctors in the United States who took a placebo (i.e., a pill that, unknown to the participants in the study, contained no active ingredients), 189 suffered heart attacks during the five-year period of the study.
p(placebo) = 189/11034 = 0.01713
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Is there evidence that the proportion having heart attacks is significantly lower for the male medical doctors in the United States who received the buffered aspirin every other day than for those who received a placebo?
Ha: p(aspirin)-p(placebo) < 0
Does this lead you to believe that taking one buffered aspirin every other day is effective in reducing the incidence of heart attacks?
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Ho: p(asprin) - p(placebo) = 0
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I ran a 2-PropZTest to get:
test statistic = -5.00
p-value = 0.000000285
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Conclusion:
Since the p-value is extremely small reject Ho.
The aspirin a day keeps the heart attack away.
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Cheers,
Stan H.
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