Basic Probability

This is a discussion on Basic Probability within the The Foyer forums, part of the Off the Grid category; Originally Posted by TheBramble OK. Right. So the chance of my flipping a Head on any one toss of the ...

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Old Mar 27, 2009, 10:34am   #8
 
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Quote:
Originally Posted by TheBramble View Post
OK. Right.

So the chance of my flipping a Head on any one toss of the coin is 50% or 1 in 2. Which means, Iíd need to flip the coin twice to, statistically, expect to get a head. Is that correct?
yes.
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Old Mar 27, 2009, 10:34am   #9
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TheBramble started this thread
Quote:
Originally Posted by dcraig1 View Post
Possible outcomes:

H H
H T
T H
T T

=> probability of at least one head is 0.75, because all outcomes are equally likely.
No, I meant as a separate exercise. If I flip a fair coin twice, I should expect a head, statistically, as the probability of flipping a head on any one coin toss is 1 in 2. Is that correct?
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Old Mar 27, 2009, 10:39am   #10
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Originally Posted by TheBramble View Post
OK. Right.

So the chance of my flipping a Head on any one toss of the coin is 50% or 1 in 2. Which means, I’d need to flip the coin twice to, statistically, expect to get a head. Is that correct?
Yes, statistically. Try flipping a coin 100 times and I'd be surprised if the split was more exagerrated than 55/45after 100. During this 100 flips there will probably be runs of 4-5 consecutive heads or tails, and heads or tails may seem to build a lead, but by the "end" of the sample, things pretty much equate.
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Old Mar 27, 2009, 10:45am   #11
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TheBramble started this thread If the probability of my flipping a head on any one toss of a fair coin is 1 in 2 this implies that with any two tosses of the same coin, I should expect, statistically, to get (at least) one head.

(Same applies if I was looking to get a Tail, obviously.)

And if you are all correct, which Iím sure you are, that the probability of getting two consecutive heads is 1 in 4, this would imply that Iíd need to flip a fair coin 4 times to be reasonably certain, statistically, of getting (at least) one occurrence of two heads.

(Same applies if I was looking to get two consecutive tails, obviously).

Is this correct so far?
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Old Mar 27, 2009, 10:55am   #12
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Originally Posted by TheBramble View Post
If the probability of my flipping a head on any one toss of a fair coin is 1 in 2 this implies that with any two tosses of the same coin, I should expect, statistically, to get (at least) one head.

(Same applies if I was looking to get a Tail, obviously.)

And if you are all correct, which Iím sure you are, that the probability of getting two consecutive heads is 1 in 4, this would imply that Iíd need to flip a fair coin 4 times to be reasonably certain, statistically, of getting (at least) one occurrence of two heads.

(Same applies if I was looking to get two consecutive tails, obviously).

Is this correct so far?
Yes.
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Old Mar 27, 2009, 11:06am   #13
 
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yes. as per THM.
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# There are 10 kinds of people in the world; those that understand binary, and those that dont. -Anon
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# Defeat is temporary. Giving up makes it permanent. Anon
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Old Mar 27, 2009, 11:08am   #14
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TheBramble started this thread I think Iím with you all so far. Just.

If I flip a fair coin 4 times, youíre saying I could expect two consecutive tails with a probability of 1 in 4 and of two consecutive heads with a probability of 1 in 4, but I can expect two consecutive tails or two consecutive heads with a probability of 1 in 2.

Have I understood you all correctly?
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