Consider the following 2 × 2 table that shows incidence of myocardial infarc- tion (denoted MI) for women who had used oral contraceptives and women who had never used oral contraceptives. The data in the table are fictitious and are used just for illustrative purposes.
|
MI Yes
|
MI No
|
Totals
|
|
Used oral contraceptives
|
55
|
65
|
120
|
|
Never used oral contraceptives
|
25
|
125
|
150
|
|
Totals
|
80
|
190
|
270
|
Assume that the proportions in the table represent the "infinite population" of adult women. Let A = {woman used oral contraceptives} and let B = {woman had an MI episode}
a. Find P(A), P(B), P(Ac), and P(Bc).
b. What is P(A n B)?
c. What is P(A U B)?
d. Are A and B mutually exclusive?
e. What are P(A|B) and P(B|A)?
f. Are A and B independent?