Re: Moment's of student's t distribution
- To: mathgroup at smc.vnet.net
- Subject: [mg130275] Re: Moment's of student's t distribution
- From: Ray Koopman <koopman at sfu.ca>
- Date: Sun, 31 Mar 2013 03:13:10 -0400 (EDT)
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- Delivered-to: l-mathgroup@wolfram.com
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On Mar 30, 1:06 am, paul <paulvonhip... at yahoo.com> wrote:
> I'm trying to get a general formula for the moments of a non-standardized t distribution. When I ask for the moments in general --
>
> Moment[StudentTDistribution[\[Mu], \[Sigma], \[Nu]], k]
>
> -- Mathematica merely echoes the input. But when I plug in any integer for k, Mathematica gives me a simple answer quickly. How can I get Mathematica to tell me the general formula?
Are you looking for something like
mot[m_, s_, n_Integer, r_Integer] /; 0 < r < n := Sum[ Binomial[r,k]
m^(r-k) s^k n^(k/2) (k-1)!! (n-k-2)!! / (n-2)!!, {k,0,r,2}]