Genetics prob from book that I cant get (probability type)

[BruceZ]

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[img]/images/graemlins/grin.gif[/img] You don't think its safe to say that people without the disease don't have symptoms?

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That would depend on the symptoms. If the symptoms are an occasional runny nose, then almost everyone without the disease would have this symptom. People can show symptoms of a disease without having a disease, or they could have a different disease. Google munchausen.

[madnak]

1/4 is the clear answer, and should be intuitive to anyone with an understanding of poker theory. Whoever wrote that book should avoid cards. This sounds like the Monty Hall fallacy.

[CallMeIshmael]

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Out of curiosity, how did the manual do it?

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Probability of him having disease = Probability of him having Hh * probability of not showing disease
= 1/2*1/3
= 1/6

[CallMeIshmael]

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1/4 is the clear answer, and should be intuitive to anyone with an understanding of poker theory. Whoever wrote that book should avoid cards. This sounds like the Monty Hall fallacy.

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Exactly.

I sat there, and reread the problem probably 5 times thinking that there had to be some wording that I wasnt seeing (there solution is correct if the problem is "what are the chances he will have the disease and not show it by the age of 50?") but there wasnt

It was just one of the biggest errors people can make in this type of problem, and Im fairly shocked it made it into print

[vhawk01]

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1/4 is the clear answer, and should be intuitive to anyone with an understanding of poker theory. Whoever wrote that book should avoid cards. This sounds like the Monty Hall fallacy.

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Exactly.

I sat there, and reread the problem probably 5 times thinking that there had to be some wording that I wasnt seeing (there solution is correct if the problem is "what are the chances he will have the disease and not show it by the age of 50?") but there wasnt

It was just one of the biggest errors people can make in this type of problem, and Im fairly shocked it made it into print

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Right, but if that was the question, it is precisely NOT a Bayes question, and it defeats the whole point. Most students can probably multiply fractions. Understanding conditional probability was (I would guess) the point of the exercise, and the answer specifically didn't do that.

[Big Poppa Smurf]

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um this sounds really simple? its 50/50 to have it or not, and 67/33 to express it or not, so 33% of 50?

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this is what the book did, and perhaps im reading too much into it, but this was not my answer

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yeah i'm not smart

edit: but i also never learned this "bayes" theorem you all speak of