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#1 2013-10-29 23:58:27
- vermanerds
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- Registered: 2013-10-29
- Posts: 3
Random indicator variables- probability
The answer using recursive method was 2.71 from memory. However I am unable to prove it through random indicator variables method
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#2 2013-10-30 00:08:21
- vermanerds
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- Registered: 2013-10-29
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Re: Random indicator variables- probability
sorry I'm new and did not upload the actual photo.
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#3 2013-10-30 02:39:11
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
Hi;
Welcome to the forum, I do not agree with your answer of 2.71. I am getting 5 / 2.
This agrees with my simulation of 100000 games.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#4 2013-10-30 02:49:19
- vermanerds
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- Registered: 2013-10-29
- Posts: 3
Re: Random indicator variables- probability
sorry, yes. I was thinking the 2.71 was from a previous question. Thank you, my apologizes
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#5 2013-10-30 03:04:40
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
Hi;
I can probably do that with a Markov chain too.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#6 2013-11-01 03:02:22
- gAr
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- Registered: 2011-01-09
- Posts: 3,482
Re: Random indicator variables- probability
Hi,
Start with a probability tree as in the figure.
A indicates Ann's turn and B indicates Bob's turn.
Rectangular nodes are the faces shown by the die.
The expected number of turns to end the game is
Last edited by gAr (2013-11-01 03:03:00)
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
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#7 2013-11-01 04:11:16
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
Hi gAr;
Nice answer. That is the correct recursive answer unlike the one given in post #2 that gets 5.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#8 2013-11-01 04:29:27
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Random indicator variables- probability
Hi bobbym,
I read only the question in the first box there, so gave the recursive solution!
Anyway, why do they ask it to be solved by a particular method, to make the answer evaluation easier?
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
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#9 2013-11-01 04:31:15
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
I never did figure that sort of thing out.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#10 2013-11-01 04:35:25
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Random indicator variables- probability
And I never heard of "indicator random variable" and "geometric random variable" till now, I only knew random variable!
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
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#11 2013-11-01 04:41:07
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
I do not know what an indicator variable is either. I would have to look it up.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#12 2013-11-01 04:45:26
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Random indicator variables- probability
Okay, need to take a break, see you later.
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
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#13 2013-11-01 04:54:59
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
Hi;
Seems I spoke to soon, see Ross' book on probability.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#14 2013-11-01 16:23:28
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Random indicator variables- probability
Hi,
Kenneth Ross? What about that book?
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
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#15 2013-11-01 21:25:17
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
It is supposed to cover the use of indicator variables.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#16 2013-11-02 00:19:26
- gAr
- Member
- Registered: 2011-01-09
- Posts: 3,482
Re: Random indicator variables- probability
Okay, I'll check that sometime.
"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?
"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."
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#17 2013-11-02 00:35:29
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Random indicator variables- probability
They are mentioning section 7.2, I have not looked at it yet. It is supposed simplify expectation problems.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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