解题方法
1 . 已知随机变量X,Y,Z满足X~N(3,
),Y~N(1,
),Z=Y-1,且P(X>4)=0.1,则P(Z2<1)的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/742d3e642d52e01899f66df411100838.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/742d3e642d52e01899f66df411100838.png)
A.0.1 | B.0.2 |
C.0.8 | D.0.9 |
您最近一年使用:0次
名校
2 . 已知随机变量
服从正态分布
,若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f8fc0f7475a487a1ed8059ad78cd9dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/030f01a4363bf6c103ccf1ca07c6f49d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0c6aee43a67236b3d5106121722ba1d.png)
A.0.3 | B.0.4 |
C.0.7 | D.0.2 |
您最近一年使用:0次
解题方法
3 . 现有下面四个命题:
①若
,则
;
②若
,
,则
;
③如果今天是2021年6月22日(星期二),那么两百天后是星期六;
④若数列
满足
,
,则由数学归纳法可证明
.
其中所有真命题的序号是( )
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ba6958aaeaff136a1fa10ff70524fa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d547a6a4a49cffcabf867378a306b8c9.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa00c97e6e59067be9ff785460f4ef05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18684b1566cc0590e61fc691179f469b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba4b139d0a946d9f28517ecce87a4009.png)
③如果今天是2021年6月22日(星期二),那么两百天后是星期六;
④若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13a6e1d671215fc96e4bee3541d1096.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d302534cc1b0f93ba57eed8a3973e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5021cd70fcdf48561b20d77157bf9c46.png)
其中所有真命题的序号是( )
A.②④ | B.②③④ | C.②③ | D.①③ |
您最近一年使用:0次
2021-07-29更新
|
101次组卷
|
2卷引用:河南省南阳市A类学校2020-2021学年高二下学期第一次阶段性检测联合考试数学(理科)试题
名校
解题方法
4 . 某校2000名学生的某次数学考试成绩
,则成绩位于区间
的人数大约是______ 人(注:若
,则
,
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661e783e829448c9d7394f8da5bdfdb0.png)
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc61ff63036f91c581f0bb1db1925522.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15f990a004c60ffc733edf06cf7a5595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/122a298ff9bb7de9fa955904139463bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/547c0c665547bc6181ed9aec23df6d74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1a969d4d89489db55540bca6e204669.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661e783e829448c9d7394f8da5bdfdb0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c522959e54b3fa8aacbccef7feacbfc1.png)
您最近一年使用:0次
2021-07-13更新
|
188次组卷
|
2卷引用:河南省商周联盟2020-2021学年高二下学期6月联考数学理科试题
解题方法
5 . 设随机变量
服从正态分布
,且
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f8fc0f7475a487a1ed8059ad78cd9dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/708e43476e58ae258952fab2ecc830cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/829ab9264a2397ee50d01519f2b44c09.png)
A.0.34135 | B.0.3173 | C.0.1586 | D.0.1585 |
您最近一年使用:0次
6 . 一鲜花店销售某种玫瑰花,根据以往的日销售记录,这种玫瑰花的日销售额(单位:元)服从正态分布
在销售记录中,随机抽取
天,至少有一天日销售额在
之外的概率约为0.0257.在这
天里,鲜花店老板每天给表现最好的5位员工每位两次抽奖的机会,每次抽奖结果只有“100元和50元”两种结果,由于某种原因,二者出现的概率不一定是等可能的,设出现“100元”的概率为
,各次抽奖相互独立.
(1)求
的值;
(2)当有10人次参与抽奖时,恰有6人次得到100元的概率为
,求
的最大值点
,当
时,设每位员工抽奖得到的金额为
,预计在这
天里,鲜花店老板需要拿出的抽奖金额的期望是多少?
附:若随机变量
服从正态分布
,则
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00a258ad2a8bfbe73a9705a7ec298c1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfd0e1bdcd33f2528e9bf98e9097167f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)当有10人次参与抽奖时,恰有6人次得到100元的概率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed1f109f79547d6ae0d94339e689e8f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed1f109f79547d6ae0d94339e689e8f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3606c4a853a6a34cb7f33bea81b15a1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098e663b79254b0a2e0e00f92bd14b8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
附:若随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8b9ad2fcfff3dd546c5fdbedfe6238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bcc248a7770a16fa10fc4602d71e0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cbc6f5e62ef3d8f0cf7976294b23755.png)
![]() | ![]() | ![]() | ![]() |
您最近一年使用:0次
名校
7 . 已知随机变量
服从正态分布
,且
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/778dfb406e5ca6131f7e39a1cdf145c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e72ddc82291133ee149a059fe5d62cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ee26716325b853577d2f2d37bca7320.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2021-05-08更新
|
1009次组卷
|
5卷引用:河南省新乡市辉县市第一高级中学2020-2021学年高二下学期第二次阶段性考试数学(理)试题
名校
解题方法
8 . 在一次期中考试中某校高三年级学生数学成绩
服从正态分布
,若
,且
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6da1f5237231a622c9eb0773dc160a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c778252b3034eafd0679e728a27d3069.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73d21ec389c260bbb22e4ae20c822d4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec240da1786daed247e80824d2a7e6b3.png)
A.0.2 | B.0.3 | C.0.35 | D.0.4 |
您最近一年使用:0次
2021-04-29更新
|
1202次组卷
|
3卷引用:河南省新乡市辉县市第一高级中学2020-2021学年高二(培优班)下学期第二次阶段性考试数学(理)试题
20-21高三下·河南·阶段练习
名校
解题方法
9 . 已知随机变量
服从正态分布
,若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29bcc248a7770a16fa10fc4602d71e0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8395464e439742ee658d230823a910e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34cc61df8a8f3dc5e83997c30e3bae7d.png)
A.0.1 | B.0.2 | C.0.3 | D.0.4 |
您最近一年使用:0次