題組內容

5. Let $X$ and $Y$ be two random variables with joint p.d.f. given by: (10 分) \[ f(x,y) = y \cdot e^{-x}, 0 < y \le x < \infty \]

(b) Calculate the conditional probability \( P(X > 2\ln(2) | Y = \ln(2)) = ? \)