A nationwide survey conducted by the National Cancer Society revealed the following information: Of 10,000 people surveyed, 3,300 were "heavy coffee drinkers" and 160 had cancer of the pancreas. Of those who had cancer of the pancreas, 142 were heavy coffee drinkers. Using the data in this survey, determine whether the events "being a heavy coffee drinker" and "having cancer of the pancreas" are independent events.

Question

Quizplus · Accepted Answer

If the events were independent, then the probability of being a heavy coffee drinker and having cancer of the pancreas would be the product of their individual probabilities. However, in this case, the probability of having cancer of the pancreas is higher among heavy coffee drinkers (142/3300 = 0.043) than among non-heavy coffee drinkers (18/6700 = 0.003), indicating that the events are not independent.

A Nationwide Survey Conducted by the National Cancer Society Revealed