SOLUTION: After studying Mr X's family history, a doctor determines that the probability of any child born to this couple having a gene for disease X is 1 out of 4. If Mr X has three childr

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: After studying Mr X's family history, a doctor determines that the probability of any child born to this couple having a gene for disease X is 1 out of 4. If Mr X has three childr      Log On


   

Question 1192115: After studying Mr X's family history, a doctor determines that the probability of any child born to this couple having a gene for disease X is 1 out of 4. If Mr X has three children, what is the probability that exactly two of the children have the gene for disease X?

Answer by ikleyn(52794) About Me  (Show Source):
You can put this solution on YOUR website!
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After studying Mr X's family history, a doctor determines that the probability of any child
born to this couple having a gene for disease X is 1 out of 4. If Mr X has three children,
what is the probability that exactly two of the children have the gene for disease X?
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Standard binomial distribution problem. 

    P = C%5B3%5D%5E2%2A%281%2F4%29%5E2%2A%281-1%2F4%29%5E1 = 3%2A%281%2F4%29%5E2%2A%283%2F4%29 = 0.1406  (rounded).    ANSWER

Solved.

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To see many other similar  (and different)  solved problems,  look into the lessons
    - Simple and simplest probability problems on Binomial distribution
    - Typical binomial distribution probability problems
in this site.

Learn the subject from there.