设离散型随机变量
可能取的值为
,
,
,
(
),若
的数学期望
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892560dcff6af9f66a3f735652f69dd7.png)
_____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1369d5308a7af510cd1e8505ceee62a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90de8c0588e022b64be34e79244a1889.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97b6228ae9d60be6c65eff485d9ed8ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892560dcff6af9f66a3f735652f69dd7.png)
更新时间:2020-02-04 09:35:02
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【知识点】 利用随机变量分布列的性质解题解读
相似题推荐
填空题-单空题
|
适中
(0.65)
名校
【推荐1】设随机变量
的概率分布如下表所示,且随机变量
的均值
为2.5 ,
则随机变量
的方差
为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fc79c66ebaacd709ec9965b90a22b14.png)
1 | 2 | 3 | 4 | |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca4b1f3e80fc9ed2446311381e3bd909.png)
您最近一年使用:0次
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适中
(0.65)
名校
解题方法
【推荐2】已知随机变量
的分布列如下:且
,则实数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
____________ ,若随机变量
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70feead3889f6ef3135a6be6137c7bd9.png)
____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ec04ea8037e6a1f8059dec3c84ee340.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f26f7e4191458fd5c60673156af73d31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70feead3889f6ef3135a6be6137c7bd9.png)
![]() | 2 | 3 | 4 |
![]() | ![]() | ![]() | ![]() |
您最近一年使用:0次