Medical researchers believe that the probability of getting lung cancer if a person smokes is 0.34. The probability that a nonsmoker will get lung cancer is 0.03. It is also known that 11% of the population smokes. What is the probability that a person with lung cancer is a smoker?

Therefore the probability that a person with lung cancer is a smoker is

 = 0.58

Step-by-step explanation:

Given, 11% of population smokes. Then(100-11)%=89% of population do not smoke. The probability of getting lung cancer if a person smoker is 0.34. The probability that a nonsmoker will get lung cancer is 0.03.

                        Cancer

Smoker           (11%× 0.34)=3.74%

nonsmoker     (89%×0.03)=2.67%

                                        ______

                                            6.41%

Therefore the probability that a person with lung cancer is a smoker is

= 0.58

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional