Calculating Marginal Density and Expectation of Project Cost

[afireinside]

Homework Statement

Let the joint density of the material and labor cost of a project be modeled by
f_x,y(u,v) = 2v*e^-v*(2+u) u,v ≥ 0
= 0 otherwise

a) find marginal density of X and Y
b) find E(Y)

Homework Equations

Marginal density of Y should be ∫f_x,y(u,v) du from 0 to ∞, unless there is some other relationship between X and Y, and u and v that I am missing. I get undefined when trying to do this integral, so I know it can't be right.

 

[Ray Vickson]

Homework Statement

Let the joint density of the material and labor cost of a project be modeled by
f_x,y(u,v) = 2v*e^-v*(2+u) u,v ≥ 0
= 0 otherwise

a) find marginal density of X and Y
b) find E(Y)

Homework Equations

Marginal density of Y should be ∫f_x,y(u,v) du from 0 to ∞, unless there is some other relationship between X and Y, and u and v that I am missing. I get undefined when trying to do this integral, so I know it can't be right.

Homework Statement

Homework Equations

The Attempt at a Solution

Show your work; the integration gives a simple, finite answer, so you must be doing something wrong.