1. A study of personality and heart disease followed a large random sample of individuals for four years. At the outset, none of them had coronary heart disease (CHD), but over time some developed it. Also, participants took a test to determine how likely they were to experience sudden anger; on this basis they were classified as low, moderate or high anger personalities. At the conclusion of the study, these were the results:
(a) Do the study’s data support the widespread belief that greater susceptibility to anger puts individuals more at risk of heart disease? Express the risk of a high anger person developing CHD as an approximate multiple of that of a low anger person.
(b) What portion of the individuals developing CHD had low anger personalities? High anger personalities? How do you reconcile these results with those you calculated for part (a) of this question?
2. Although the exact rate is variable, rapid antigen covid tests generate false negative results in as many as 20% of individuals actually infected with the virus. For the purposes of this problem, assume the false negative rate is exactly 20% in all such cases and there are no false positives. Suppose 20 people at a party take an antigen test, and 3 of them actually have covid. What is the probability that no more than one of the partiers will test positive?
