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bkk145
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A recent married couple decided to have four kids. What is 25 Aug 2007, 08:40
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A recent married couple decided to have four kids. What is the probability that they will have exactly 2 boys and 2 girls?



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A recent married couple decided to have four kids. What is 25 Aug 2007, 09:04
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the probability for G or B is 1/2

1/2*1/2*1/2*1/2 = 1/16

BBGG = 1/16
BGBG = 1/16
BGGB = 1/16
GBGB = 1/16
GBBG = 1/16
GGBB = 1/16

1/16+1/16+1/16+1/16+1/16+1/16 = 6/16 = 3/8

:-D
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A recent married couple decided to have four kids. What is 25 Aug 2007, 09:29
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KillerSquirrel
the probability for G or B is 1/2

1/2*1/2*1/2*1/2 = 1/16

BBGG = 1/16
BGBG = 1/16
BGGB = 1/16
GBGB = 1/16
GBBG = 1/16
GGBB = 1/16

1/16+1/16+1/16+1/16+1/16+1/16 = 6/16 = 3/8

:-D
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I'm trying to see what's wrong with my method...if you can help.
I got the same answer using the method above. However, when I use this method, I get different answer:
Say if you have the first 2 child, you have have either BB,BG,GB,GG. This means that the first 2 child doesn't affect the probability. So, wouldn't the last two child pick would be 1/2 * 1/2 = 1/4?
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A recent married couple decided to have four kids. What is 25 Aug 2007, 10:18
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bkk145
KillerSquirrel
the probability for G or B is 1/2

1/2*1/2*1/2*1/2 = 1/16

BBGG = 1/16
BGBG = 1/16
BGGB = 1/16
GBGB = 1/16
GBBG = 1/16
GGBB = 1/16

1/16+1/16+1/16+1/16+1/16+1/16 = 6/16 = 3/8

:-D

I'm trying to see what's wrong with my method...if you can help.
I got the same answer using the method above. However, when I use this method, I get different answer:
Say if you have the first 2 child, you have have either BB,BG,GB,GG. This means that the first 2 child doesn't affect the probability. So, wouldn't the last two child pick would be 1/2 * 1/2 = 1/4?
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I don't think you can solve this problem two kids at a time.

:-D
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Fistail
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A recent married couple decided to have four kids. What is 25 Aug 2007, 16:42
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bkk145
A recent married couple decided to have four kids. What is the probability that they will have exactly 2 boys and 2 girls?
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2 b and 2 g = 4!/2!2! = 6
total = 2^4 = 16
prob = 6/16 = 3/8
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There is a faster way to solve those kind of questions, but I think this is out of scope.

Applying the binomial distribution formula:

https://www.answers.com/topic/binomial-distribution

C(n,k)*p^k*(1-p)^(n-k)

p = the probability for a certain event = 1/2 (getting a boy)

1-P = the completing event = 1/2 (getting a girl)

n = total items in the group = 4

k = desired outcome = two boys = 2

solving

C(4,2)*(1/2)^(2)*(1/2)*(4-2) = 6*1/4*1/4 = 6/16 = 3/8

:-D
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A recent married couple decided to have four kids. What is 25 Aug 2007, 23:33
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KillerSquirrel
There is a faster way to solve those kind of questions, but I think this is out of scope.

Applying the binomial distribution formula:

https://www.answers.com/topic/binomial-distribution

C(n,k)*p^k*(1-p)^(n-k)

p = the probability for a certain event = 1/2 (getting a boy)

1-P = the completing event = 1/2 (getting a girl)

n = total items in the group = 4

k = desired outcome = two boys = 2

solving

C(4,2)*(1/2)^(2)*(1/2)*(4-2) = 6*1/4*1/4 = 6/16 = 3/8

:-D
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yup i was looking for the binomial formula.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
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Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!