填空题:某工厂的次品率为2％，而正品中有90％的产品为一等品，从该厂中任意取出一件检验，检验结果为一等品的概率为______。

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设随机变量X～B(4，0．5)，Y服从区间[2，6]上的均匀分布，则E(2X—Y)=()。

A 0 B 2 C -2 D 4

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设X、Y为随机变量，D(X)=4，D(Y)=16，Cov(X，Y)=2，ρXY=（）。

A <img src="https://www.beizhujiaoyu.com/uploads/202208/164696753423221.png" width="16" height="34" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/164696753918381.png" width="16" height="34" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/164696754380491.png" width="15" height="33" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/164696754778961.png" width="15" height="34" />

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设随机变量X的E(X)=2，D(X)=3，用切比雪夫不等式估计P{|X—E(X)|≤3}≥ ()。

A <img src="https://www.beizhujiaoyu.com/uploads/202208/164696899974471.png" width="15" height="34" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/164696900340461.png" width="16" height="34" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/164696900891461.png" width="16" height="34" /> D 2

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A 均匀 B 泊松 C 指数 D 二项

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A <img src="https://www.beizhujiaoyu.com/uploads/202208/164696757766701.png" width="34" height="34" /> B 0 C <img src="https://www.beizhujiaoyu.com/uploads/202208/164696758051901.png" width="16" height="34" /> D 无法计算

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（）。

A <img src="https://www.beizhujiaoyu.com/uploads/202208/164696700674351.png" width="17" height="34" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/164696701086791.png" width="16" height="34" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/164696701431021.png" width="14" height="34" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/164696701949111.png" width="15" height="33" />

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设随机变量X服从参数λ=2的泊松分布，F(x)为X的分布函数，则下列正确的是()。

A P(X≤1)=2e-2 B F(1)=e-2 C F(0)=e-2 D P(X=0)=P(X=1)

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袋中装有7个白球和8个黑球，一次取出4个球后，发现是同一种颜色的，这种颜色是黑色的概率为()。

A <img src="https://www.beizhujiaoyu.com/uploads/202208/164696894177451.png" width="15" height="33" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/164696894572691.png" width="15" height="33" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/164696895024591.png" width="15" height="34" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/164696895659491.png" width="16" height="34" />

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A <img src="https://www.beizhujiaoyu.com/uploads/202208/1646976596461.png" width="16" height="34" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/164697660049761.png" width="16" height="34" /> C 1 D <img src="https://www.beizhujiaoyu.com/uploads/202208/164697660650141.png" width="16" height="34" />

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（）。

A <img src="https://www.beizhujiaoyu.com/uploads/202208/164697473279741.png" width="15" height="34" /> B 1 C 2 D <img src="https://www.beizhujiaoyu.com/uploads/202208/164697473724631.png" width="16" height="34" />

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填空题:某工厂的次品率为2％，而正品中有90％的产品为一等品，从该厂中任意取出一件检验，检验结果为一等品的概率为______。

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