Another probability question

This is a discussion on Another probability question within the General Trading Chat forums, part of the T2W Archive category; Say you have a coin weighted to show heads 60% of the time. How many coin tosses are needed to ...

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Old Jun 6, 2011, 11:06am   #1
 
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Another probability question

Say you have a coin weighted to show heads 60% of the time. How many coin tosses are needed to have 90% confidence of getting more heads than tails?
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Old Jun 6, 2011, 11:08am   #2
Joined Jan 2011
Re: Another probability question

toss the coin until you have more heads than tails.

then you can be 100% confident that you have more heads than tails.
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Old Jun 6, 2011, 11:24am   #3
Joined Jun 2011
Re: Another probability question

The market is very slow today and coin tossing seems to be all the rage. I am curious, though. Why go to all that trouble only to make the coin weighted for 60% heads ? If you are going to tamper with it, isn't it better to make both sides of the coin heads ? Then you are 100% certain of a win, 100% of the time.

Also is there something special about 60% that people keep mentioning it. I am puzzled as I prefer 100%.
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Old Jun 6, 2011, 1:20pm   #4
Joined Apr 2008
Re: Another probability question

I prefer a coin with 30% heads that pays 10 heads and losses 1 for tails.

Expected win: 0.3 x 10 - 0.7 x 1 = 2.3

What about that?

I agree, nothing special with 60%. It is just a bug in their head. They need some reprogramming.
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Old Jun 6, 2011, 1:35pm   #5
 
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Re: Another probability question

WinstonSmith started this thread That's all well and good Albert - top marks for understanding expectancy. But can you solve the probability question?
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Old Jun 6, 2011, 1:44pm   #6
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Re: Another probability question

2.512941595
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Old Jun 6, 2011, 1:49pm   #7
 
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Re: Another probability question

WinstonSmith started this thread I feel some uncertainty Mr Bramble...
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Old Jun 6, 2011, 1:53pm   #8
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Re: Another probability question

That's definitely a good thing.
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