Quote:
|
Originally Posted by KennyVictor
At the risk of being seen as a bad loser (or looser in some circles) I consider this a badly worded question. Just the sort of question a study of statistics is likely to engender as we all know statisticians like their figures to mean what the statistician wants them to mean.
Scenario 1. A family has two children and one of them is a girl therefore it is logical to assume one of them isn't. I mean how many non statisticians would say "I have two children, one is a girl and the other is a girl."
So: Answer to the original question 100%
Scenario 2. We see a picture of the unfortunate statisticians children, they aren't attractive, in fact you can't tell what sex they are with their clothes on. The statistician points to one and says 'She is a girl'. What's the other one then we wonder and of course the answer is 50/50 it's a boy since it's a even chance either way.
So: Answer to the original question 50%
The 66% scenario is more of a play on words than a sensible question.
Well, someones gotta be controversial. Crash has dissappeared and P57 has a fortnight in the sin bin.
KV
|
The important thing in this exercise was that some people should realise they have gaps in their basic probability skills and try to take steps to remedy them, and thus save themselves fiscal grief.
But you cannot resist playing the fool to dumb down this resource even further.
I wonder how much the management appreciate this when they are trying to use this forum to market intelligent rating systems based on mathematical modelling.
As far as I can see Woof's presentation of a classical probability puzzle is correct.
Quote:
|
Originally Posted by Woof
You are told that a family has two children. You are also told that one of those two children is a girl.
|
It is wrong to infer that a parent of the kids told you this.
It is wrong to infer that you were shown a picture of them.
It is also wrong to infer as CP later did, that the firstborn was a girl (or in his argument "a heads").
And it is beneath contempt to try to sabotage a philanthropic effort just because your feathers are ruffled.
As it is wrong for Iomaca to commend both of you in your recalcitrance.
Informing me that he once regularly mentally calculated Harmonic Means does not impress me in the slightest. Aiding and abetting such an orgy of ignorance depresses me considerably.