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Topic: Random numbers
Replies: 64   Last Post: Dec 24, 2007 1:04 PM

 Messages: [ Previous | Next ]
 b92057@yahoo.com Posts: 1,187 Registered: 4/18/05
Re: Random numbers
Posted: Dec 22, 2007 7:30 PM

On Dec 22, 10:16 am, quasi <qu...@null.set> wrote:
> On Fri, 21 Dec 2007 10:57:00 -0800 (PST), simple.pop...@gmail.com
> wrote:
>
>
>

> >On Dec 21, 11:37 pm, bill <b92...@yahoo.com> wrote:
> >> On Dec 21, 3:16 am, John <iamach...@gmail.com> wrote:
>
> >> > Given a function that returns a random number between 1-5, write one
> >> > that returns a random number between 1-7 for the case when it should
> >> > be integer and for the case it can be real.

>
> >> Let S be the function that generates a RN between 1 and 5. Then
>
> >> T = S_1 + S_2 + ... + S_7
>
> >> For the reals , RN_7 = T/7
>
> >May be this should fix it:
>
> >For the reals , RN_7 = 1 + (T-7)*3/14
>
> Yes, that fixes the range.
>
> But it's still biased (that is, not a unform distribution).
>
> quasi

The OP does not specify a uniform
distribution, merely the range.

RN_7 = T/7 satisfies the range 1 thru 7.

T/7 is a numner in the range 1 thru 7,
but is it random?

If RN_7 = T mod 7 +1, the probability
of a correct guess is 1/7

If RN_7 = T/7, the probability
of a correct guess is < .11 if you always
guess that T = 21 or 22

Bill J

Date Subject Author
12/21/07 Champ
12/21/07 quasi
12/21/07 quasi
12/21/07 Phil Carmody
12/21/07 quasi
12/21/07 quasi
12/21/07 Phil Carmody
12/21/07 quasi
12/21/07 Phil Carmody
12/21/07 Phil Carmody
12/21/07 quasi
12/21/07 quasi
12/21/07 Phil Carmody
12/21/07 quasi
12/21/07 Phil Carmody
12/21/07 Phil Carmody
12/21/07 quasi
12/21/07 Phil Carmody
12/21/07 quasi
12/21/07 Marshall
12/21/07 Phil Carmody
12/21/07 quasi
12/21/07 Phil Carmody
12/21/07 Marshall
12/21/07 briggs@encompasserve.org
12/21/07 William Elliot
12/21/07 quasi
12/22/07 William Elliot
12/21/07 Pubkeybreaker
12/21/07 b92057@yahoo.com
12/22/07 quasi
12/21/07 simple.popeye@gmail.com
12/21/07 simple.popeye@gmail.com
12/22/07 quasi
12/22/07 Gib Bogle
12/22/07 quasi
12/21/07 Marshall
12/22/07 simple.popeye@gmail.com
12/22/07 quasi
12/22/07 simple.popeye@gmail.com
12/22/07 quasi
12/22/07 quasi
12/22/07 quasi
12/22/07 simple.popeye@gmail.com
12/22/07 quasi
12/23/07 simple.popeye@gmail.com
12/23/07 simple.popeye@gmail.com
12/23/07 simple.popeye@gmail.com
12/23/07 simple.popeye@gmail.com
12/23/07 simple.popeye@gmail.com
12/22/07 simple.popeye@gmail.com
12/22/07 Herman Rubin
12/22/07 b92057@yahoo.com
12/22/07 quasi
12/23/07 b92057@yahoo.com
12/23/07 quasi
12/23/07 b92057@yahoo.com
12/24/07 quasi
12/24/07 quasi