Question

A study of consumer smoking habits includes 193 people in the 18-22 age bracket (60 of whom smoke), 127 people in the 23-30 age bracket (35 of whom smoke), and 96 people in the 31-40 age bracket (23 of whom smoke). If one person is randomly selected from this sample, find the probability of getting someone who is age 23-30 or smokes.
A. 0.084
B. 0.589
C. 0.505
D. 0.276

Answer 1

Total number of people in the sample = 193 + 127 + 96 = 416

Probability of picking 23-30 year old = 92 /416 = 0.2212 ( not including the people who smoke)

Number of people who smoke = 60+35+23 = 118 people

Prob(someone who smokes) = 118/416 = 0.2837

So required probability = 0.2837 + 0.2212 = 0.505 (answer)