4. Let X1, X2, ..., Xn be independent and identically distributed random samples of size n from a population with pdf given by 3x f(x) = 03 for 0 < x < 0, and 0 otherwise. Define W = min(X1, X2,, Xn) and Y =max (X1, X2,, Xn). 4.b) Find the joint pdf of (W, Y). Specify the support of the distribution. (3 pts)