试题与答案

设随机变量X在区间[-1,2]上服从均匀分布,随机变量 则方差D(Y)=___

题型:填空题

题目:

设随机变量X在区间[-1,2]上服从均匀分布,随机变量


则方差D(Y)=______.

答案:

参考答案:[*]

解析:[考点提示] 方差.
[解题分析] 已知X在区间[-1,2]上服从均匀分布,则X的概率密度为
[*]
因此[*]
于是
[*]
所以[*]

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