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#51 2013-03-31 10:32:19

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

Okay, I will wait till then.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#52 2013-03-31 12:48:35

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

Hi Agnishom;

I am getting ≈ 0.077 for c).


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#53 2013-03-31 15:11:22

Agnishom
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From: The Complex Plane
Registered: 2011-01-29
Posts: 14,189
Website

Re: rat run probability

How?

My Approach was like this: P(starting from 1) = (No. of times it starts from 1 and leaves through 3)/(No.of times it leaves through 3)


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#54 2013-03-31 15:16:18

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

Hi;

That is very difficult to answer when someone gets an programming answer that may be incorrect or may not be.

Your reasoning looks okay. But 35%? Doesn't that seem a little high to you after all it only starts in 1, 25% of the time.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#55 2013-03-31 15:24:01

Agnishom
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From: The Complex Plane
Registered: 2011-01-29
Posts: 14,189
Website

Re: rat run probability

You are correct but what should I do now?


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#56 2013-03-31 15:27:16

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

anonimnystefy and I just were discussing c) and he showed me where I was going wrong with it too. This is a difficult one to do by simulation because it has a conditional probability in it.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#57 2013-03-31 15:38:31

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

Are you sure you are counting the events correctly?


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#58 2013-03-31 15:40:52

Agnishom
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From: The Complex Plane
Registered: 2011-01-29
Posts: 14,189
Website

Re: rat run probability

Have you done it?


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#59 2013-03-31 15:41:35

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

Hmmm, you are never sure of anything, I could be making a mistake. That is why I stress having at least two methods. One checks the other.

But do you agree 35% is too high?


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#60 2013-03-31 15:43:25

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

bobbym wrote:

Hmmm, you are never sure of anything, I could be making a mistake. That is why I stress having at least two methods. One checks the other.

But do you agree 35% is too high?

I was talking to Agnishom.

Hi Agnishom

bobbym has done it and I believe his answer is correct.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#61 2013-03-31 15:57:22

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

The simulation looks okay to get the numerator and the denominator. I am looking for an analytical solution to back up the simulation!

A very rough analysis gives 1 / 16 which is close to the simulation.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#62 2013-03-31 16:14:01

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

Could you run the simulation a gew more times and post the results?


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#63 2013-03-31 16:17:20

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

Same thing, I suspect the exact answer is 1 / 13.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#64 2013-03-31 16:18:55

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

1/13 is the correct answer. Remember our friend Bayes?


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#65 2013-03-31 16:24:30

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

He is no friend of mine. Lucky he is long since gone.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#66 2013-03-31 16:26:44

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

A figure of speech.

Have you tried using the Bayes' theorem. It gives 1/13, whoch agrees with your simulation!


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#67 2013-03-31 16:28:47

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

I have not tried it, how did you set it up?


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#68 2013-03-31 16:34:54

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

Just plugged the numbers in.

P(A|B)=P(B|A)*P(A)/P(B)= (2/13)*(1/4)/(1/2)=1/13.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#69 2013-03-31 16:37:38

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 14,189
Website

Re: rat run probability

A smiley?


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#70 2013-03-31 16:38:21

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

Ah, thanks, bobbym.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#71 2013-03-31 16:40:17

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

That looks simplest.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#72 2013-03-31 22:56:36

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

It is. I was amazed when I figured it out.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#73 2013-03-31 22:59:21

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

Yes, you did well. Very good!


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

#74 2013-03-31 23:18:44

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,804

Re: rat run probability

Thanks. Have you figured out what went wrong in Agnishom's simulation?


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#75 2013-03-31 23:20:20

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,386

Re: rat run probability

I have not seen it yet. He might have a logic error in the program.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Online

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