In: Math
3. A device runs until either 2 components fails, at which the device stops running. Let X and Y be the lifetimes in hours of the first and second component, respectively. The joint probability density function of the lifetimes is:
f(x,y) = { (x+y)/27 : 0 < x < 3, 0< y < 3
{ 0
a) Find the marginal probability density function of X and the marginal probability density function of Y.
b) Are X and Y independent? Why or why not?
c) Find the conditional density of X given that Y = y
d) Find the expected value of X given that Y =1/4
Please show your work, I have an exam tomorrow, thank you!