SOLUTION: 40% of Country A are smokers, when the same moment 20% of Country B and 30% of Country C are smokers too. Also, it is given that people from Country A consist of 20% of the populat

Algebra ->  Probability-and-statistics -> SOLUTION: 40% of Country A are smokers, when the same moment 20% of Country B and 30% of Country C are smokers too. Also, it is given that people from Country A consist of 20% of the populat      Log On


   

Question 855527: 40% of Country A are smokers, when the same moment 20% of Country B and 30% of Country C are smokers too. Also, it is given that people from Country A consist of 20% of the population of all the tree countries(A,B,C) and that people from Country C consist of 50%.



a) A civilian is chosen randomly from the total population of all the three countries. What is the probability that he's smoker?

b) Granted that he's smoker, what is the probability that he comes from Country A?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

	POP	smoker	% of total P

A	0.2	0.4	0.08

B	0.3	0.2	0.06

C	0.5	0.3	0.15

			0.29

P(smoker) = .2*.4 + .2*.3 + .3*50 = .08 + .06 + .15 = .29

P(A|smoker) = .08