Question 572774
P(X=x) G 5/9 B 3/8 
What is the probability that within the first 7 births the family will have at least 2 boys?
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Ans: P(2<= x <=7) = 1 - P(0<= x <=1) = 1 - [P(x = 0)+P(x = 1)]
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= 1 - [(3/8)^7 + 7C1(5/9)(3/8)^6]
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= 1 - [0.001+ 0.0108]
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= 1 - [0.0109]
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= 0.9891
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Cheers,
Stan H.
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