Probability

  • Thread starter roystonteo via OfficeKB.com
  • Start date
R

roystonteo via OfficeKB.com

For U.S. live births, P(Boy) and P(Girl) are approximately 0.51 and 0.49
respectively. According to a newspaper article, a medical process could alter
the probabilities that a boy or a girl will be born. Researchers using the
process claim that coupleswho wanted a boy were successful 85% of the time,
while couples who wanted a girl were successful 77% of the time. Assuming the
medical process does not have an effect on the sex of the child:

a. Without medical intervention, what is the probability of having a boy?
ANS: =BINOMDIST(0,1,0.85,FALSE)

b. With medical intervention, what is the conditional probability that a
couple who wants a boy will have a boy?
ANS: =BINOMDIST(0.51,1,0.85,FALSE)

c. With medical intervention, what is the conditional probability that a
couple who wants a girl will have a girl?
ANS: =BINOMDIST(B11,1,0.77,FALSE)

Please advise me if i am on the right track or if my answer is correct or
wrong?
 
J

Joel

What is your sample size?

If you two babies It is .51^2 that they are both boys and .49^2 that they
are both girls which will be 100% boys or 100% girls (approximately 25%).
You will not get the same results if you had a sample size of 10 babies.

You don't need normal distribution to make this calculation. It is a
straight probability calculation the way you have the question worded.
 
R

roystonteo via OfficeKB.com

Dear Joel,

But the answer has to be in some excel probability function.
There is no sample size, which means i need to add in the sample size myself
or what?
Can you show me one answer so i know which direction to move.

Thank you
What is your sample size?

If you two babies It is .51^2 that they are both boys and .49^2 that they
are both girls which will be 100% boys or 100% girls (approximately 25%).
You will not get the same results if you had a sample size of 10 babies.

You don't need normal distribution to make this calculation. It is a
straight probability calculation the way you have the question worded.
For U.S. live births, P(Boy) and P(Girl) are approximately 0.51 and 0.49
respectively. According to a newspaper article, a medical process could alter
Click to expand...
[quoted text clipped - 16 lines]
Please advise me if i am on the right track or if my answer is correct or
wrong?
Click to expand...
Click to expand...
 
M

Mike Middleton

roystonteo -
For U.S. live births, P(Boy) and P(Girl) are approximately 0.51 and 0.49
respectively. ... a. Without medical intervention, what is the probability
of having a boy? <
Click to expand...

0.51

I may decide to limit my responses to only one homework question per week.

- Mike
 
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