Let X and Y be continuous random variables having joint density, f,
given by f(x,y) = ((lambda)^2)(e^[(-lambda)(y)], for 0<x<y and
f(x,y)=0 elsewhere.  Find the marginal densities for f(x) and f(y) for
X and Y respectively.

Note: For "0<x<y" the 'less than' signs are "less than or equal to."  Also
f(x) has a subscript X, and f(y) has a subscript Y.

Please include all work as well as references to any theorems,
postulates, or lemmas used to solve this problem.

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Clarification of Question by funkyworms-ga on 05 Dec 2005 12:46 PST

This question must be answered by 12/06/05 at 7am Central Standard
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