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Best Answer bonanova, 27 April 2014 - 05:53 AM

Suppose John tosses a coin 250 times and Eric tosses a coin 251 times, what is the probability that john's coin has more heads than Eric?  What is the probability that Eric has more heads than John?

 

Spoiler for Looks like

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9 replies to this topic

#1 BMAD

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Posted 11 April 2014 - 07:51 PM

Suppose John tosses a coin 250 times and Eric tosses a coin 251 times, what is the probability that john's coin has more heads than Eric?  What is the probability that Eric has more heads than John?


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#2 Rob_G

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Posted 11 April 2014 - 08:39 PM

Spoiler for I'd say Eric...


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#3 bonanova

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Posted 13 April 2014 - 07:53 AM

Spoiler for Looks like


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The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
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#4 Rob_G

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Posted 14 April 2014 - 04:13 PM

Spoiler for I think John has


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#5 BMAD

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Posted 15 April 2014 - 01:19 AM

Spoiler for I think John has


Why?
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#6 Rob_G

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Posted 15 April 2014 - 04:26 PM

 

Spoiler for I think John has


Why?

 

 

Spoiler for My reasoning...

 

Spoiler for As a side note


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#7 dgreening

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Posted 23 April 2014 - 02:22 PM

Spoiler for
Another perspective

 

I suspect that the impact of the extra toss is actually very small and it could go either way.

 

For 250 [or 251] tosses, you would expect some sort of distribution centered heavily around 50% [or 125 heads].

 

This is not even close to being a uniform distribution, so most points below 110 or above 140 are zero. [just a guess on the end points]. The point is that there are really only a small number of points that have to be considered.

 

Another approach might be to do some sort of convolution of the 2 distributions [which look virtually identical].

 

Since Ties go to John, the probabilityt will be less than 50%

 

Rob G may be pretty close [I am not sure].


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#8 dgreening

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Posted 23 April 2014 - 02:35 PM

Spoiler for

Edited by dgreening, 23 April 2014 - 02:37 PM.

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#9 dgreening

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Posted 23 April 2014 - 02:59 PM

 


Edited by dgreening, 23 April 2014 - 03:00 PM.

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#10 bonanova

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Posted 27 April 2014 - 05:53 AM   Best Answer

Suppose John tosses a coin 250 times and Eric tosses a coin 251 times, what is the probability that john's coin has more heads than Eric?  What is the probability that Eric has more heads than John?

 

Spoiler for Looks like


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The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell




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