• 2022-06-26
    ​一枚硬币连续掷20次,X表示正面出现次数的总和,估计P{8A: [img=59x25]1803da34a770ae4.png[/img]
    B: [img=98x29]1803da34b074375.png[/img]
    C: [img=82x25]1803da34b9da472.png[/img]
    D: [img=98x29]1803da34c2db871.png[/img]
  • 举一反三