推 goshfju :下面那題建議用mgf做比較快 結果會是 Γ(α=2,λ) 09/14 15:11
→ goshfju :上面那題可從定義慢慢算 求 f(y)=∫f(x,y)dx 09/14 15:13
→ goshfju :f(x|y)=f(x,y)/f(y) , y=2代入得 f(x|y=2) 09/14 15:14
→ goshfju :E(X^3|Y=2)=∫x^3f(x|y=2)dx 09/14 15:14
推 david80701y :指數加指數等於Gamma，Gamma大家庭：指數，卡方分配 09/14 17:02
→ david80701y :要弄通 09/14 17:02