random variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg120451] random variables*From*: paulvonhippel at yahoo <paulvonhippel at yahoo.com>*Date*: Sat, 23 Jul 2011 19:52:50 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

I would like to define a symbol representing a random variable, and then use that symbol in other expressions. It's not clear to me how to do that. For example, when I type the following input -- U = ChiSquareDistribution[n - 1] V = 2*U W = 3*U Mean[V] Mean[W] -- I do not get the mean of the random variables V and W. I know I can get the desired answer by typing: V = TransformedDistribution[2*U, U \[Distributed] ChiSquareDistribution[n - 1]] W = TransformedDistribution[3*U, U \[Distributed] ChiSquareDistribution[n - 1]] Mean[V] Mean[W] But that requires me to redefine the distribution of U every time I need it. Is there a way to define U just once?

**Follow-Ups**:**Re: random variables***From:*DrMajorBob <btreat1@austin.rr.com>