Let fxy18 0y4 yxy2 be the joint pdf of X and Y a Sketch the
Let f(x,y)=1/8, 0y4 yxy+2 be the joint pdf of X and Y.
(a) Sketch the region for which f(x,y)>0
(b) Find fx(x), the marginal pdf of X.
(c) Find fy(y), the marginal pdf of Y.
(d) Determine h(y|x) the conditional pdf of y given X=x.
(e) Determine g(x|y) the conditional pdf of x given Y=y.
(f) Compute E{Y|x}
(g) Is the conditional mean of Y a linear function of x?
Please show me the solution plz.
Solution
Here y varies from 0 to 4, x from y to y+2
fx(x) = \\int_{0}^{4}\\frac{dy}{8}
= 0.5, 0<x<2
------------------------------------------------
c) fy(y) = \\int_{0}^{2}\\frac{dx}{8}
= 0.25, 0<=y<=4
-----------------------------------------
f(x) f(y) = 0.5(0.25)
= 1/8
Hence x and y are independent.
d) h(y/z) = h(y) = 0.25, 0<y<2
e) G(x/y) = fx(x) as x and y are independent.
f) E(Y./x) = E(Y) = 2
g) No not a linear funciton
