SOLUTION: 10. A population survey shows that 40% are Young, 35% are Middle aged, and the rest are Seniors. Among the Young, 60% smoke. Among the Middle aged, 40% smoke, while among the Senio

Algebra ->  Probability-and-statistics -> SOLUTION: 10. A population survey shows that 40% are Young, 35% are Middle aged, and the rest are Seniors. Among the Young, 60% smoke. Among the Middle aged, 40% smoke, while among the Senio      Log On


   

Question 868500: 10. A population survey shows that 40% are Young, 35% are Middle aged, and the rest are Seniors. Among the Young, 60% smoke. Among the Middle aged, 40% smoke, while among the Seniors 20% smoke. Find the probability that a person in this survey:
a) a middle aged smoker
b) a senior non smoker
c) a smoker
d) a smoker given that he/she is a senior
e) a senior given that he/she smokes
f) young or a smoker
I have the answers I just don't understand how to do it
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

Recommend making a table to keep track...

Age     % of Pop  %whosmoke   % of Entire Pop for each

Young     .40       .60          .24    (.40*.60)

Middle    .35       .40          .14

Seniors   .25       .20          .05

                                 .43 (sum)

a) a middle aged smoker: P(MA smoker) = .14

 b) a senior non smoker: P(S nonsmoker) = 1 - .05 = .95  0r 95%

 c) a smoker P = .43

 d) a smoker given that he/she is a senior: P = .05/.25

 e) a senior given that he/she smokes:    P =  .05/.43

 f) young or a smoker: P =  .40 + .43 - .24