People who get angry easily tend to have more heart disease.
Problem: That's the conclusion of a study that followed a random sample of 12,986 people from three locations for about four years. All subjects were free of heart disease at the beginning of the study. The subjects took the Spielberger Trait Anger Scale test, which measures how prone a person is to sudden anger. Here are data for the 8474 people in the sample who had normal blood pressure. CHD stands for "coronary heart disease." This includes people who had heart attacks and those who needed medical treatment for heart disease.
|
|
Low anger
|
Moderate anger
|
High anger
|
Total
|
|
CHD
|
53
|
110
|
27
|
190
|
|
No CHD
|
3057
|
4621
|
606
|
8284
|
|
Total
|
3110
|
4731
|
633
|
8474
|
Required:
(a) What percent of all 8474 people with normal blood pressure had CHD?
(b) What percent of all 8474 people were classified as having high anger?
(c) What percent of those classified as having high anger had CHD?
(d) What percent of those with no CHD were classified as having moderate anger?
(e) Do these data provide any evidence that as anger score increases, the percent who suffer CHD increases? Explain.