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Forum index » Science and Technology » Math » Probability » Prediction
noob stat question
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Nephi
science forum beginner


Joined: 16 Jun 2006
Posts: 1

PostPosted: Fri Jun 16, 2006 6:14 pm    Post subject: noob stat question Reply with quote

(If this is the wrong place to ask this forgive me.)

Suppose you randomly choose n numbers from some range (say 0 to 1). Call
the smallest one m. What is the expected value for m?

Thanks



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abose
science forum beginner


Joined: 16 Jun 2006
Posts: 8

PostPosted: Fri Jun 16, 2006 8:00 pm    Post subject: Re: noob stat question Reply with quote

The CDF (Cumulative Distribution Function) of M is P(M<x)=P(M<all n
numbers)=x^n.
So PDF (density) of M is n*x^(n-1). This, incidentally, is Beta(n+1,1)
distribution.

So E(M)=Integrate[x*n*x^(n-1), {x,0,1}]=1/(1+n)


Nephi wrote:
Quote:
(If this is the wrong place to ask this forgive me.)

Suppose you randomly choose n numbers from some range (say 0 to 1). Call
the smallest one m. What is the expected value for m?

Thanks



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Posted via a free Usenet account from http://www.teranews.com
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