投擲一公正錢幣三次，隨機變數 X 表三次投擲中出現反面的次數，試求 X 的變異數為何？(A) 0 (B) (C) (D)

問題詳情

29. 投擲一公正錢幣三次，隨機變數 X 表三次投擲中出現反面的次數，試求 X 的變異數為何？
(A) 0
(B)
(C)
(D)

參考答案

答案：D
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)

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