Question

Find the indicated probability. Show work

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). If one person is randomly selected from this sample, find the probability of getting someone who is age 18-22 or does not smoke.

Answer 1

Total people = 186 + 124 + 99 = 409

Total people of age 18-22 = 186

Total people of who smoke = 42 + 40 + 21 = 103

Total people of who don't smoke = 409 - 103 = 306

P(age 18-22 or does not smoke) = P(age 18-22) + P(does not smoke) - P(age 18-22 and doesn't smoke)

                                                     = 186/409 + 306/409 - (186-42)/409

                                                     = 0.851