The following data comes from the 2011 Behavioral Risk Factor Surveillance System (BRFSS) survey, which is run by the Centers for Disease Control (CDC). This is a joint probability table for the proportions of survey respondents who smoke and who have had heart attacks.
Smoker, Non-Smoker,
Heart Attack 0.03 0.03
No Heart Attack 0.44 0.50
Answer the following questions:
(a) What is the proportion of people who dont smoke?
(b) What is the proportion of people who dont have heart attacks?
(c) If a person is a smoker, are they more likely to have had a heart attack than someone who is not a smoker? Hint: Be careful what this question is asking!
(d) If you know someone did not have a heart attack, what is the probability that they are not a smoker? (e) Is smoking independent of having a heart attack?