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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 4:44 pm
(This post was last modified: March 13, 2016 at 4:50 pm by IATIA.)
(March 13, 2016 at 4:31 pm)Mr.wizard Wrote: The probability of picking a 1 car from behind 3 doors is always 33%, it doesn't matter if 100 people play the game and guess right 100 times, each game is independent and every contestant starts with a 33% chance of picking right. Using the coin flip analogy, if you flip a coin 10 times and it lands on heads 9 times does that mean that the probability of flipping a coin and having it land on heads is 90%? Of course not its a 50/50 probability.
Yes, that is so on the first go around, but if one door is opened and you are given a second chance to choose it changes everything. See my post above. There is a 2/3 chance that the other door will contain the car on the second go around. Because one has a 1/3 chance of having a car already, there is a 2/3 chance that one of the other doors has the car. Monty opened one which means there is a 2/3 chance that the other door has the car.
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 4:49 pm
(March 13, 2016 at 4:44 pm)IATIA Wrote: (March 13, 2016 at 4:31 pm)Mr.wizard Wrote: The probability of picking a 1 car from behind 3 doors is always 33%, it doesn't matter if 100 people play the game and guess right 100 times, each game is independent and every contestant starts with a 33% chance of picking right. Using the coin flip analogy, if you flip a coin 10 times and it lands on heads 9 times does that mean that the probability of flipping a coin and having it land on heads is 90%? Of course not its a 50/50 probability.
Yes, that is so on the first go around, but if one door is opened and you are given a second chance to choose it changes everything. See my post above. There is a 2/3 chance that the other door will contain the car on the second go around.
Yes I know I already argued the second choice is 2/3, I was responding to penguin saying that the probability of 1 out of 3 can not be a guaranteed 33%
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 4:56 pm
I missed that, your post was several away from his/hers/their's/whoever.
You make people miserable and there's nothing they can do about it, just like god.
-- Homer Simpson
God has no place within these walls, just as facts have no place within organized religion.
-- Superintendent Chalmers
Science is like a blabbermouth who ruins a movie by telling you how it ends. There are some things we don't want to know. Important things.
-- Ned Flanders
Once something's been approved by the government, it's no longer immoral.
-- The Rev Lovejoy
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 4:59 pm
(March 13, 2016 at 4:16 pm)robvalue Wrote: I've never had anyone get so angry about probability before.
When I've taught it in the past, if I got any signs of life out of my students I was doing well. Really? I've seen a genetics class go bat shit over these two truths:
1 The probability of tossing 100 heads in a row is astronomical.
2. If you have just tossed 99 heads in a row, the chances of tossing another head is 50%.
Anger, fear, doubt, it was all there. Counter intuitive truths scare people. Shall we discuss economics. It's scary for many of the same reasons.
If there is a god, I want to believe that there is a god. If there is not a god, I want to believe that there is no god.
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 5:04 pm
So long as we can post supply and demand graphs.
I'm always surprised when people talk about the pros/cons of minimum wage they never post S&D graphs to show equilibrium distortion. Makes things so much more visual.
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 8:44 pm
Yeah I think ep's trolling now. He's saying two things essentially: 1) the laws of probability only work if you assume that the person doesn't have a way to make them not work (I don't know what this could possibly mean... esp? X-ray vision?) and 2) it's rude of us to want him to have a better chance of winning because the comfort he gets from going with his gut is worth more than 1/3*((value of car)-(value of goat)).
I refuse to believe anyone could seriously propound those two viewpoints consecutively
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Don't worry, my friend. If this be the end, then so shall it be.
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 9:24 pm
(This post was last modified: March 13, 2016 at 9:28 pm by ErGingerbreadMandude.)
Oh. My. God.
Initially there are 3doors inside which what we know not of (is that a correct sentence!?)
So the chance of getting a goat is not 50-50.
But after the host reveals a goat behind a door and asks you whether you want to switch :
You could have either chosen a goat initially.
You could have chosen a car initially.
Saying that the probability is not 50-50 is saying that Monty opens a door behind which he has a car and then asks you to switch. Shit damn.
Asking me to believe that the chance is not 50-50 is asking is to go against my common sense. There are two options car and goat, there are two doors, the chance of having chosen a goat initially is 50-50.
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 10:07 pm
(March 13, 2016 at 9:24 pm)pool the great Wrote: Oh. My. God.
Initially there are 3doors inside which what we know not of (is that a correct sentence!?)
So the chance of getting a goat is not 50-50.
But after the host reveals a goat behind a door and asks you whether you want to switch :
You could have either chosen a goat initially.
You could have chosen a car initially.
Saying that the probability is not 50-50 is saying that Monty opens a door behind which he has a car and then asks you to switch. Shit damn.
Asking me to believe that the chance is not 50-50 is asking is to go against my common sense. There are two options car and goat, there are two doors, the chance of having chosen a goat initially is 50-50.
No, it's not and it has been explained why it is not.
"Common sense" does not trump mathematics.
Skepticism is not a position; it is an approach to claims.
Science is not a subject, but a method.
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 10:23 pm
Now I feel like putting a kitten in boiling water ? 
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RE: The role of probability in solving the Monty Hall problem
March 13, 2016 at 10:24 pm
Exactly the reason why I said you people have the right mathematical answer not the right answer.
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