Scenario: A study of consumer smoking habits includes 186 people in the 18-22 age bracket
(42 of whom smoke), 124 people in the 23-30 age bracket (40 of whom smoke), and 99
people in the 31-40 age bracket (21 of whom smoke).
Group smoke
18-22 age
23-30 age
31-40 age
total
2. P (yes smoke)
Yes
3. P (NO 23-30 age)
42
4. P (23-30 age NO)
40
Answer in reduced fractions
21
1. P (18-22 or does smoke)
103
No
144
84
78
306
total
186
7. P(No)=
124
99
409
5. P (31-40 age No)
6. P (Yes and 31-40 age)
8. P(31-40 age or yes)=