Take the 2-minute tour ×
Mathematica Stack Exchange is a question and answer site for users of Mathematica. It's 100% free, no registration required.

For 617519 first time births there were 317528 boys. Give an estimate with 99% confidence interval for the probability that the first time birth is a boy.

I have searched for the confidence interval function. However, I cannot find any match with probability and confidence interval within the HypothesisTesting package.

The result I am looking for is:

(*0.51255,0.51583*)
share|improve this question

1 Answer 1

up vote 4 down vote accepted

The ratio is the estimate of the p parameter for presumed binomial distribution. The central limit theorem justifies use of the normal approximation for calculation of interval.

n = 617519;
m = 317528;
p = m/n;
z = Quantile[NormalDistribution[], {0.005, 0.995}]
ci =p + # Sqrt[(1/n) p (1 - p)] & /@ z

yielding:

{0.512561, 0.515838}
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.