名校
1 . 设随机变量
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2cc7c2be240fb89a84a77e3e2050a9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96a071e7713ad0d06a0b6b1c91c5a99e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15ccf465956d37df86150d9f60516f68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2cc7c2be240fb89a84a77e3e2050a9d.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2019-07-01更新
|
448次组卷
|
3卷引用:江西省九江市实验中学2021-2022学年高二下学期5月阶段性水平测试数学(理)试题
2 . 以下命题中:①为了了解
名学生对学校某项教改试验的意见,打算从中抽取一个容量为
的样本,考虑用系统抽样,则分段的间隔
为
;②线性回归直线方程
恒过样本中心
,且至少过一个样本点;③在某项测量中,测量结果
服从正态分布
.若
在
内取值的概率为
,则
在
内取值的概率为
;其中真命题的个数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4f0e3992efedab109b99e6e172e6238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b72ac611ae66b86761e080761d9aabc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b72ac611ae66b86761e080761d9aabc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f6f99ae110662590f31df7ca8f88dba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65680835f51aaa806d290deb43acb81b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e48e54f2ce3af12221046e3306aab395.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e31d9bb923c80fd2ae124f9672b6bd79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e48e54f2ce3af12221046e3306aab395.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fd43309fe7fcf7e1da6b2cd72441ffe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a87796ee30e6c5d5e6b6285b32abe10c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e48e54f2ce3af12221046e3306aab395.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c4ee2317e88e36c08a58dac8658bc87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29be23f689eb01e57963495377501257.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2016-12-04更新
|
271次组卷
|
3卷引用:江西省九江市实验中学2021-2022学年高二下学期5月阶段性水平测试数学(理)试题
11-12高三下·江西赣州·阶段练习
解题方法
3 . 国家公务员考试,某单位已录用公务员5人,拟安排到
三个科室工作,但甲必须安排在
科室,其余4人可以随机安排.
(1)求每个科室安排至少1人至多2人的概率;
(2)设安排在
科室的人数为随机变量
,求
的分布列和数学期望.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(1)求每个科室安排至少1人至多2人的概率;
(2)设安排在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
您最近一年使用:0次