SOLUTION: Assume that the probability is 1/2 that a child born is a boy. What is the probability that of four children in a family two are girls and two are boys.

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Question 1184815: Assume that the probability is 1/2 that a child born is a boy. What is the probability that of four children in a family two are girls and two are boys.
Answer by ikleyn(52800) About Me  (Show Source):
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Assume that the probability is 1/2 that a child born is a boy.
What is the probability that of four children in a family two are girls and two are boys.
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It is a typical and a classic Binomial distribution problem.


The number of trials n= 4; the probability of the success trial is  1%2F2,  and the number of success trials k = 2. 


    P = C%5B4%5D%5E2%2A%281%2F2%29%5E2%2A%281-1%2F2%29%5E%284-2%29 = 6%2A%281%2F2%29%5E2%2A%281%2F2%29%5E2 = 6%2A%281%2F2%29%5E4 = 0.375.     ANSWER

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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.