• 2022-10-30
    设随机变量X服从[tex=3.929x1.357]xBzoxjKLUz9GDg/21RL7MQ==[/tex]正态分布,且二次方程[tex=5.286x1.357]ZcWDJ6sfjxiJ/g07w2pzNg==[/tex]无实根的概率为[tex=0.786x2.357]iBwfnCQwh5632Co4+X5bhQ==[/tex],求[tex=0.643x1.0]R8j6nFNrQJBYHOT5c6hCaw==[/tex]的值。
  • 解:依假设[tex=0.786x2.357]iBwfnCQwh5632Co4+X5bhQ==[/tex]=P(方程[tex=5.286x1.357]ZcWDJ6sfjxiJ/g07w2pzNg==[/tex]无实根)[tex=7.143x1.357]6zAnFPWwmT2v0Ple3l1BiA==[/tex]  [tex=20.571x2.786]E7mQxEx0pe3wDdrQy1BErm/Ym5gFFtktY+AWwdNkhm5ibAkAd+MMGoFYCYTUsrxRTnJLt7j69PhQ/BBmvYU9SaCAG2Jt93x72xfT4nk9pxaMVccZslb8sB8H/pWpkNcr[/tex]所以[tex=3.571x2.357]S+GqRHNCrPJH/cO9oF0Y/53Rm1oo0Ea3uaui+jB1pYA=[/tex],即[tex=1.929x1.214]W8DnqMFUJZhEfJRdPIDxnQ==[/tex]。[br][/br]

    内容

    • 0

      随机变量X服从参数为[tex=0.643x1.0]7dwHQGHL24uGORI8NryViw==[/tex]的泊松分布,且已知[tex=8.571x1.357]gWyoTuxxsfaBqL4MAoQPzg==[/tex],则[tex=0.643x1.0]7dwHQGHL24uGORI8NryViw==[/tex]=[input=type:blank,size:4][/input].

    • 1

      设A,B为随机事件,且[tex=10.214x1.357]UFhh7/cpKKWawNqEi6sjCpOpLq0k8cDY7nota3iXRLyElYdvOpoixiscUXp1gtcQ[/tex].[tex=5.786x1.357]qyuQ5CEmb7pnFEdSJagrL3ZfRRUo8o/wFxvkJYZhkYE=[/tex]令[tex=8.5x3.643]vblEuTPqIaJpcqun4w9VWTFA76feOldODM1wV3P55TypLcK4oSC9pOqm2yRXANpXbezM/KNCrlQREAqEfwbEDA==[/tex][tex=8.429x3.643]54pWBVUeFJVlU+jOrHcDD0z6bSZCCbjPzTV1IiKdRRo7q6hAT11E2WX4PhyIykpp5IX8oG/DWqy269UEH6LPz+5punRBzjatdSEktQD1TP0=[/tex]求:二维随机变量(X,Y)的概率分布;

    • 2

      设随机变量 [tex=0.857x1.0]KGogyvwDAIJf/iL0H/9wjg==[/tex] 与 [tex=0.643x1.0]jDVSpgNhHe+VJmgvx3gg1Q==[/tex] 相互独立,且服从参数为 1 的指数分布. 记 [tex=13.5x1.357]ZrmgIX329+lIMwj+0JP7oX4KmceUiv4NOTdLGvSfjGFY26aIR9qNFK9EJaP3gu/x[/tex] 求[tex=3.857x1.357]t0PsS3YAPSnhTBV9LUFwGQ==[/tex]

    • 3

      设随机变量(X,Y)的概率分布列为[img=345x154]178ab1c9ce3bc1b.png[/img]求[tex=1.571x1.0]JUrGU6ftUjxQCIr6CyfDwQ==[/tex],[tex=1.357x1.0]yL/7/hhyqgwzAX8jnIq3OQ==[/tex],[tex=4.357x1.357]LN0xwhQHSOeLwBClUlpHQw==[/tex].

    • 4

      设随机变量X与Y,且D(X)=25 . D(Y)=36 .[tex=6.929x1.357]YRHgHmN/yZW92ECOHesamh6DUEs33HnR+2dxr68Tcr4=[/tex]求[tex=4.286x1.357]wxsI0NJpCsUWd6vdcOiJiw==[/tex]