Re: [問題] 動差母函數
※ 引述《jacky123 (上班很累啦)》之銘言:
: Mx(t)=1/4(3e^t+e^-t)
: 求期望值變異數
: 請問變異數
: 是 零or0.5呢
: 謝謝
By the uniqueness of mgf, we know that
X have the pdf as follows:
x 1 -1
f(x) 3/4 1/4
( Mx(t)=E(e^tX)=Σ(e^tx)*f(x)=3/4*e^t+1/4*e^-t )
Compute the E(X) and Var(X) by the definitions of them!
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 203.73.183.95
推
02/16 01:04, , 1F
02/16 01:04, 1F
※ 編輯: jangwei 來自: 203.73.183.95 (02/16 01:07)
推
02/16 01:28, , 2F
02/16 01:28, 2F
推
02/16 06:27, , 3F
02/16 06:27, 3F
→
02/16 06:29, , 4F
02/16 06:29, 4F
討論串 (同標題文章)