3 ms·
The expected number of sons is 1, and the expected number of daughters is 1 (by the framing of the problem, in every possible scenario, there is exactly one dau
by DalekBaldwin 8y ago
The expected number of sons is 1, and the expected number of daughters is 1 (by the framing of the problem, in every possible scenario, there is exactly one daughter), but the expected value of the ratio is not 1:1. E[X]/E[Y] = E[X/Y] is not a valid identity.
http://www.thebigquestions.com/2010/12/22/a-big-answer-2/ http://www.thebigquestions.com/2010/12/22/a-big-answer-2/
- Pristina 8y agoI read that and it seems wrong. The question asked "what fraction of the pop is female" but his argument is that 3 families of 4 girls and 1 family of 12 boys make the fraction of girls in the average family 75% (the average of 100% x3 and 0% x1) which is non-sensical to me. >E[X]/E[Y] = E[X/Y] is not a valid identity. is completely irrelevant here because it is being used to point out that a non-answer is wrong.
- DalekBaldwin 8y agoHe starts with a simpler problem to elucidate the principle that is key to the original problem. Do continue reading.