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两道概率论题目不会,求助各位大神

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IP属地:广东1楼2023-12-12 20:58回复
    (5)
    X~B(2,p)
    P(X≥1)=8/9
    1-P(X=0)=8/9
    1-(1-p)^2 =8/9
    2p-p^2 =8/9
    9p^2-18p+8=0
    (3p-2)(3p-4)=0
    p=2/3 or 4/3 (rej)
    ie
    p=2/3
    Y~ B(4,p)~B(4,2/3)
    P(Y≥1)
    =1-P(Y=0)
    =1-(1-2/3)^4
    =1- 1/81
    =80/81
    (9)
    F(X)
    =0 , x<0
    =x/2 , 0≤x<2
    =1 , x≥2
    P(X<1/2)
    =F(1/2)
    =1/4


    IP属地:中国香港5楼2023-12-13 16:04
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