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katastrofa
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Joined: August 16th, 2007, 5:36 am
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Re: Proportion of boys to girls, if continues to have children until a boy

October 31st, 2018, 8:13 pm

Ppauper's solution is incorrect, because the ratio estimators are known (at least to statisticians) to be biased: from Jensen's inequality E(x/y) >= E(x) / E(y). The consecutive trials are not independent, because only couples which produce boys stop. Consequently, there will always be more girls in a finite population.
I'm not sure if the author of the question was actually aware of the above (or of the fact that for discreet variables, it's called a discrete probability distribution, not a probability density function).
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