Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Got it,

Thanks bobbyM and gAr

So after all this isn't related to Bayes'?

'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'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Why do you say that?

**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.**

Offline

Because I don't see where you use 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'

I'm not crazy, my mother had me tested.

Offline

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi Agnishom,

It is related to Bayes', we just didn't write a formula for that!

"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."

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

There is a formula that covers what he did, it is called the extended form of Bayes theorem.

**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.**

Offline

I tried to match that too.

p(a|b) = (p(b|a)*p(a))/((p(b|a)*p(a))+(p(b|not a)*p(not a))

'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'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

What you wrote is the extended form:

That has the form of his answer. That is what I was working on, trying to fill that in but I must have missed something.

His use of the tree is better, it lends itself to computation better.

**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.**

Offline

Surely thats better.

But how do you use that formula?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

I thought of something like:

and we have

"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."

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

Look at his answer:

then look at the formula:

try replacing corresponding parts.

I did not see gAr's answer until I posted. He got the solution so he is the guy to ask.

**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.**

Offline

Now in that part, what does A and B stand for?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi Agnishom;

You are forgetting that I did not get the answer so I must not have filled that formula in correctly.

**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.**

Offline

Okay, I am contended with the tree anyway. Next time I will think of one

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

gAr wrote:

I thought of something like:

and we have

Yes, yes, it seems more clear but how does it fit into the formula?

I mean how do you relate the calculation with it?

*Last edited by Agnishom (2013-04-06 03:07:09)*

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi,

You can plug in the values now..

"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."

Offline

Okay! Thanks

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

I found a couple of pages that agree with his approach and also calculate the number for you.

**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.**

Offline

Webpages?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

Hi;

Yes, websites. Have not gone over them completely so I do not know how good their computations are.

**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.**

Offline

May I have the link?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 108,492

**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.**

Offline

*A bag contains 5 balls. Two balls are drawn and are found to be white. *

What is the probability that all the balls are white?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,840

Insufficient information for a solution. You might as well ask, if I draw two whites what is the probability that the next person to knock on my door has no trousers on.

It isn't a Bayes problem, as there are not two events.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

That is what I suspected.

Let me show you the solution and please tell me if you can digest it.

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

Sandeep wrote:

PIf P(A)=probability of getting the bag chosen for drawing balls when all the 5 balls in the bag are white.

P(B)=probability of getting the bag chosen for drawing balls when only 4 balls in the bag are white

P(C)=probability of getting the bag chosen for drawing balls when only 3 balls in the bag are white

P(D)=probability of getting the bag chosen for drawing balls when only 2 balls in the bag are white

P(E)=probability of getting two white balls drawn from the bag

P(E/A)=probability of two white balls drawn when the bag is chosen which has all white balls in it

P(E/B)=probability of two white balls drawn when the bag is chosen which has only 4 white balls in it

P(E/C)=probability of two white balls drawn when the bag is chosen which has only 3 white balls in it

P(E/D)=probability of two white balls drawn when the bag is chosen which has only 2 white balls in it.

So using baye's theorem

required probability

*Last edited by Agnishom (2014-10-05 07:07:52)*

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline