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Question regarding probability

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mukesh tiwari

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Jan 17, 2012, 12:46:32 PM1/17/12
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Hello all
I am stuck with this problem. There are 37 people in group . What is
the probability that at least 3 of them have their birthday in the
same month.

Regards
Mukesh Tiwari

Joe Fineman

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Jan 17, 2012, 5:34:40 PM1/17/12
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mukesh tiwari <mukeshtiw...@gmail.com> writes:

> I am stuck with this problem. There are 37 people in group . What is
> the probability that at least 3 of them have their birthday in the
> same month.

1.

This is a pigeon-hole problem.
--
--- Joe Fineman jo...@verizon.net

||: To discover why one was right can be illuminating. :||

Frederick Williams

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Jan 19, 2012, 10:48:00 AM1/19/12
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mukesh tiwari wrote:
>
> Hello all
> I am stuck with this problem. There are 37 people in group . What is
> the probability that at least 3 of them have their birthday in the
> same month.

The question is unanswerable unless one knows how the members of the
group are chosen.

--
When a true genius appears in the world, you may know him by
this sign, that the dunces are all in confederacy against him.
Jonathan Swift: Thoughts on Various Subjects, Moral and Diverting

Herman Rubin

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Jan 19, 2012, 3:34:26 PM1/19/12
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On 2012-01-19, Frederick Williams <freddyw...@btinternet.com> wrote:
> mukesh tiwari wrote:

>> Hello all
>> I am stuck with this problem. There are 37 people in group . What is
>> the probability that at least 3 of them have their birthday in the
>> same month.

> The question is unanswerable unless one knows how the members of the
> group are chosen.

I claim, with no further information, that the probability is 1
that at least 4 have their birthday in the same month.


--
This address is for information only. I do not claim that these views
are those of the Statistics Department or of Purdue University.
Herman Rubin, Department of Statistics, Purdue University
hru...@stat.purdue.edu Phone: (765)494-6054 FAX: (765)494-0558

Pavel314

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Jan 21, 2012, 5:31:55 PM1/21/12
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On Jan 19, 3:34 pm, Herman Rubin <hru...@skew.stat.purdue.edu> wrote:
Agree with the 4 at p=1.

There are 12 months so the most spread out the birth months can be
over 37 people is if 11 of the months have 3 members of the group of
37 in them and the 12th. month has 4.
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