• 2022-05-28
    已知X~B(n,p),且E(X)=2,D(X)=1.6,,则有()
    A: n=5,p=0.4
    B: n=10,p=0.2
    C: n=4,p=0.5
    D: n=8,p=0.25
  • B

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    • 0

      设X~B(n,p),且E(X)=2.4,D(X)=1.44,则 A: n=12,p=0.2 B: n=8,p=0.3 C: n=6,p=0.4 D: n=4,p=0.6

    • 1

      ‌已知随机变量X服从B ( n , p ),E(X) = 4,D(X) = 3.6,则( ).​ A: n = 20,p = 0.2 B: n = 40,p = 0.9 C: n = 10,p = 0.4 D: n = 40,p = 0.1

    • 2

      已知X~b(n,p),且E(X)=2.4,D(X)=1.44,则 A: n=4,p=0.6 B: n=6,p=0.4 C: n=8,p=0.3 D: n=24,p=0.1

    • 3

      已知随机变量X服从B ( n , p ),E(X) = 2.4,D(X) = 1.68,则( ). A: n = 4,p = 0.6 B: n = 6,p = 0.4 C: n = 8,p = 0.3 D: n = 24,p = 0.1

    • 4

      设X~B(n,p),且E(X)=2.4,D(X)=1.44,则n,p的值为( ) A: n=4,p=0.6 B: n=6,p=0.4 C: n=8,p=0.3 D: n=24,p=0.1