[機統] 請教一題統計

[dearcherry11 (小笨寶)]

X1,...,Xn~N(μx,θx^2)
Y1,...,Yn~N(μy,θy^2)

那P(Xbar-Ybar>0)和P(Xbar/Ybar>1)要怎麼算??

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※ 發信站: 批踢踢實業坊(ptt.cc) 
◆ From: 140.115.229.145
→ yhliu       :條件不足, 需要假設獨立性.
→ dearcherry11:是獨立!! 我想知道相減根相除各是什麼分配~~
→ yhliu       :Xbar-Ybar～normal;
→ yhliu       :P[Xbar/Ybar>1] = P[Xbar>Ybar>0]+P[Xbar<Ybar<0]
→ yhliu       :Xbar, Ybar jointly normal.