1 . 已知
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3caaa8b048ab6c5c06634d900cfdbf0c.png)
______ .
参考数据:
,
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6488755bf1ed2024000bca9f5c5fa531.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73c8679ebd31be989c9b99cd5050cd2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3caaa8b048ab6c5c06634d900cfdbf0c.png)
参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2803f0400072db82d4d3205e5e1b3b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5e2a865f20806b4bccde38d023cf406.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2e3345835ee0d521b4c00120f3b9347.png)
您最近一年使用:0次
2 . 某食品厂为了检查一条自动包装流水线的生产情况.随机抽取该流水线上的40件产品作为样本并称出它们的质量(单位:克),质量的分组区间为
,
,…,
,由此得到样本的频率分布直方图,如图所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/11/e6933ce2-55d0-492c-9ccd-1ece02d0a8d7.png?resizew=271)
(1)根据频率分布直方图,求质量超过505克的产品数量和样本平均值
;
(2)由样本估计总体,结合频率分布直方图,近似认为该产品的质量指标值
服从正态分布
,其中
近似为(1)中的样本平均值
,计算该批产品质量指标值
的概率;
(3)从该流水线上任取2件产品,设
为质量超过505克的产品数量,求
的分布列和数学期望.
附;若
,则
,
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a7542352feb3c45e2cb39dfa85ae0f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c376aef687a9551c6825b8d82844f3c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a21c2524e572cbad4562990958110dd5.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/11/e6933ce2-55d0-492c-9ccd-1ece02d0a8d7.png?resizew=271)
(1)根据频率分布直方图,求质量超过505克的产品数量和样本平均值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbe7f95b5d89f9409ec24536da9e826.png)
(2)由样本估计总体,结合频率分布直方图,近似认为该产品的质量指标值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e381900a6e76de7d145cee30774e655d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1100379a4385b9ce064847bc21760adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbe7f95b5d89f9409ec24536da9e826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3952c93e4a74441e1b704967d13c89c3.png)
(3)从该流水线上任取2件产品,设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
附;若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73ef663ffb251a8717e48c847cdf32ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1df0bc314fa2ff0d3fea139d6d6ef04e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4621bf9b12b3fd608be540e9dbbfe4e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8c87c8e820ccde45674ffdadffd01cd.png)
您最近一年使用:0次
3 . 甲地区某次高二期末考试的某科成绩(满分
分)
服从正态分布,即
,其密度函数
,则对本次考试成绩
判断正确的有( )
(参考数据:
,
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a7afc6e67a875ed2eb889e950a77715.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e3e2dd6bfb9817b948df96d42ff2a8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a728dd7859f7fb2c6c89932c3d1c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0af927536479e1c4a6eaa423c9ce025.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c593071676b19b7dd41b093c99fc4b2.png)
A.成绩![]() ![]() |
B.成绩![]() ![]() ![]() |
C.本次考试成绩![]() ![]() ![]() |
D.若参加本次考试的考生人数为![]() ![]() ![]() |
您最近一年使用:0次
名校
4 . 若
,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5838bbd5fd44f69f22828e65ec597ae9.png)
_____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a90f12392733f7d31b5dadaa7ec2e190.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27671a7ab981e23ada2bb9da06e8f643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29c7d7cc9f6900ceb07e67e394b09f31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5838bbd5fd44f69f22828e65ec597ae9.png)
您最近一年使用:0次
2017-08-13更新
|
686次组卷
|
4卷引用:福建省南平市2016-2017学年高二下学期期末联考数学(理)试题