设为总体的一个随机样本，为的无偏估计，C＝ - 查题网

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成人高等教育 / 概率统计

设 ${ X }_{ 1 }{ ,X }_{ 2 }{ ,\cdots ,X }_{ n }\quad$ 为 $X$ 总体的一个随机样本， $E(X)=\mu ,D(X)={ \sigma }^{ 2 },$ $\hat { \theta } ^{ 2 }=C\sum _{ i=1 }^{ n-1 }{ { ({ X }_{ i+1 }-{ X }_{ i }) }^{ 2 } }$ 为 ${ \sigma }^{ 2 }$ 的无偏估计，C＝

A、
$\frac { 1 }{ n }$
B、
$\frac { 1 }{ n-1 }$
C、
$\frac { 1 }{ 2(n-1) }$
D、
$\frac { 1 }{ n-2 }$

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概率统计

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