題組內容

3. (15%) Let \( X_1, X_2 \) be a random sample of size \( n=2 \) from a distribution with p.d.f. \( f(x)=4x^3 \), \( 0 < x < 1 \), zero elsewhere. Given the ratio \( Y = X_1/X_2 \), find



(1)(10%) E(Y). (Round the answer to 4 decimal places)