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Topic: say I flip a coin 100 times...
Replies: 46   Last Post: Apr 18, 2005 9:42 PM

 Messages: [ Previous | Next ]
 George Greene Posts: 448 Registered: 12/12/04
Re: say I flip a coin 100 times...
Posted: Apr 14, 2005 1:38 PM

HERC777 wrote:
> 1,000,000 other people all flip 100 coins themselves.
> on average, will someone flip the same 100 long sequence
> I did?

NO, dumbass.

> Here's the prototype usage for average, "expected".

The expected number of flippers who will match all
100 of your flips is less than 2^(-80). That's less
than 1 over a million TO THE 8th POWER.

>
> how long a sequence will they match up to on average?

WHO are THEY? WHO is supposed to be matching WHOM?
If you are asking how long a prefix of THEIR flips
will match a prefix of YOUR flips, then the AVERAGE
length of the match is LESS THAN 1 FLIP LONG. Fully
HALF of them miss THE VERY FIRST FLIP and so have a
match-length of ZERO! When half of some things are 0,
and a quarter of them are exactly 1,
it is a lot harder for their average to get bigger than 1.

> this is nothing like, whats the average
> length sequence that matches
> between some fixed and some random sample.

It is EXACTLY like that, DIPSHIT:
The probability of two random sequences matching,
and the probability of a random sequence matching
a fixed one, ARE THE *EXACT* *SAME*. Maybe this
will be easiest for you to see when the length of the
sequence is ONE: Suppose I take a fixed sequence of
length 1: H. What is the probablity of a RANDOM sequence
of length 1, 1 coin flipped 1 time randomly, matching that?
1/2, THAT'S what.

Now, suppose I flip 2 coins randomly: what is the probability
of their matching each other?
1/2, THAT'S what.

Idiot.

Date Subject Author
4/12/05 HERC777
4/12/05 Jan Burse
4/12/05 HERC777
4/12/05 George Greene
4/13/05 Barb Knox
4/13/05 HERC777
4/13/05 Yajun
4/13/05 HERC777
4/13/05 Jay
4/13/05 HERC777
4/13/05 Jay
4/14/05 Yajun
4/14/05 George Greene
4/14/05 George Greene
4/13/05 Will Twentyman
4/13/05 briggs@encompasserve.org
4/13/05 briggs@encompasserve.org
4/14/05 George Greene
4/14/05 tchow@lsa.umich.edu
4/14/05 briggs@encompasserve.org
4/12/05 Tony
4/13/05 HERC777
4/13/05 ken quirici
4/13/05 Ralph Hartley
4/13/05 Robert Low
4/13/05 Ralph Hartley
4/13/05 Robert Low
4/13/05 tchow@lsa.umich.edu
4/13/05 HERC777
4/13/05 tchow@lsa.umich.edu
4/14/05 HERC777
4/14/05 George Greene
4/14/05 HERC777
4/15/05 tchow@lsa.umich.edu
4/15/05 tchow@lsa.umich.edu
4/16/05 George Greene
4/16/05 HERC777
4/17/05 George Greene
4/17/05 Patricia Shanahan
4/17/05 HERC777
4/18/05 Patricia Shanahan
4/17/05 tchow@lsa.umich.edu
4/18/05 HERC777
4/18/05 George Greene
4/18/05 tchow@lsa.umich.edu
4/18/05 HERC777
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