題目:設隨機變量X的分布律為P{X=k}=C*(3^k)/k!,k=0,1,2,..., 若E(X)=9/2,則D(X)= _______.
2024-11-12
題目:設隨機變量X的分布律為P{X=k}=C*(3^k)/k!,k=0,1,2,..., 若E(X)=9/2,則D(X)= _______.
A. 9/4
B. 9/2
C. 27/4
D. 81/4
正確答案:C
試題解析:暫無
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題目:設隨機變量X的分布律為P{X=k}=C*(3^k)/k!,k=0,1,2,..., 若E(X)=9/2,則D(X)= _______.
A. 9/4
B. 9/2
C. 27/4
D. 81/4
正確答案:C
試題解析:暫無