![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/df1b3caa-2092-4111-ba6e-fad01533eeba.png?resizew=386)
(1)从这20天中任选1天,求新增确诊和新增疑似的人数都超过100的概率;
(2)从新增确诊的人数超过100的日期中任选两天,用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(3)记每天新增确诊的人数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8b9ad2fcfff3dd546c5fdbedfe6238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c41d82ab5d9dcc2a42653cd252a4b3ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acea05ea67e3954ab7c782b126c46225.png)
次数 同学 | 第一次 | 第二次 | 第三次 | 第四次 | 第五次 | 第六次 | 第七次 |
甲 | 80 | 78 | 82 | 86 | 95 | 93 | — |
乙 | 76 | 81 | 80 | 85 | 89 | 96 | 94 |
(2)从甲同学进行的6次测试中随机选取4次,设X表示这4次测试成绩达到优秀的次数,求X的分布列及数学期望EX;
(3)从乙同学进行的7次测试中随机选取3次,设Y表示这3次测试成绩达到优秀的次数,试判断数学期望EY与(2)中EX的大小.(结论不要求证明)
男生:3,4,6,7,7,10,11,11,12;
女生:5,5,6,7,8,9,11,13.
假设用频率估计概率,且每个学生的阅读情况相互独立.
(1)根据样本数据,估计此次活动中学生阅读量超过10本的概率;
(2)现从该校的男生和女生中分别随机选出1人,记
![](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)
(3)现增加一名女生
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d7c7dc0f932c8cfe4fdd2ab938451bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfbc29b47b83fdc5368770b7b1acb439.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d7c7dc0f932c8cfe4fdd2ab938451bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfbc29b47b83fdc5368770b7b1acb439.png)
奖项组别 | 个人赛 | 团体赛获奖 | ||
一等奖 | 二等奖 | 三等奖 | ||
高一 | 20 | 20 | 60 | 50 |
高二 | 16 | 29 | 105 | 50 |
(2)从高一和高二获奖者中各随机抽取1人,以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(3)从获奖学生中随机抽取3人,设这3人中来自高一的人数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5c1116ce7f5a1a7b57517276d5092fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50721578c4a908b4251ef4149cecd94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eca99ebf1cca74e580eccc3b9e49064.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
假设所有病人的康复时间互相独立,从
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(1)求甲的康复时间不多于14天的概率;
(2)若康复时间大于14天,则认为康复效果不佳.设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85081df780b1f5451d55efe4f938b13e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/449f353c21e8b341b61108c5e46ee17d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09e8aac8f8318905b8a4c861c04209b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/449f353c21e8b341b61108c5e46ee17d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b2a698891d42c70b597f0da4f215f09.png)
(1)求学生甲前三次答题得分之和为4分的概率;
(2)设学生甲第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e4c651746492cce239ee6bf113242ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56b678dec65a0ca8006cc6828d8cb501.png)
(ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c5e485d34d6b30c797bf58e90efb985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/576074947c20baa9388a82b20d3bd4f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad58191cf84486be26a08508e192985e.png)
(ⅱ)写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ba8fe190e57f7b2a497c059ffb292dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7379bf07187d47913eb93a4e2f63926.png)
(ⅲ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/675c24c622664ebf9bc3d6431ca7a75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
①每位选手先闯第一关,第一关闯关成功才有机会闯第二关.
②闯关选手依次挑战.第一位闯关选手开始第一轮挑战.若第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2173a85dbdb65d601acad1b956e92e9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12444d6e8d3b097a9d090e6ed06042e4.png)
③若第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2173a85dbdb65d601acad1b956e92e9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12444d6e8d3b097a9d090e6ed06042e4.png)
④闯关进行到第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93d0f3799612b81e85b87241ec8eee68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b3323042846456d9d1446cddaddc7a.png)
(1)求随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ad5b0dc4aad791035b5c4ab87bd4702.png)
(2)若把闯关规则①去掉,换成规则⑤:闯关的选手先闯第一关,若有选手在10分钟内闯过第一关,以后闯关的选手不再闯第一关,直接从第二关开始闯关.令随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29c4cbb3a50014fa18fab2e0de87ee22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13c4f5f5dc27ad2038e23dde370f6f3c.png)
(i)求随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1fa280e86bc4aaf245fba3c37e24acd.png)
(ii)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a92ffe1d4a9db7783364527745fadc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ae7fb954b47cb67fdde891c3b9d8295.png)
(1)证明:甲、乙、丙三人中每天中午恰有一人在A食堂用餐的概率与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1b7c085e401c3ebb112604bcd96e02d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
9 . 2023年3月某学校举办了春季科技体育节,其中安排的女排赛事共有12个班级作为参赛队伍,本次比赛启用了新的排球用球已知这种球的质量指标
(单位:g)服从正态分布
,其中
,
.比赛赛制采取单循环方式,即每支球队进行11场比赛,最后靠积分选出最后冠军,积分规则如下(比赛采取5局3胜制):比赛中以3:0或3:1取胜的球队积3分,负队积0分;而在比赛中以3:2取胜的球队积2分,负队积1分.9轮过后,积分榜上的前2名分别为1班排球队和2班排球队,1班排球队积26分,2班排球队积22分.第10轮1班排球队对抗3班排球队,设每局比赛1班排球队取胜的概率为
.
(1)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8196414a210178238536a8d069756586.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28b0e97d571a182e7e6e453c54f0609e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4434bc4af81e3526be37c8839a56ec9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3a929aa6de25248bef8362b8b73d963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8633e4347b6c63b6ba7cbdb79f58406a.png)
(2)第10轮比赛中,记1班排球队3:1取胜的概率为
![](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/bdc1ff55b0d8b8ab417c8da783f2d798.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3606c4a853a6a34cb7f33bea81b15a1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(ⅰ)在第10轮比赛中,1班排球队所得积分为,求
的分布列;
(ⅱ)已知第10轮2班排球队积3分,判断1班排球队能否提前一轮夺得冠军(第10轮过后,无论最后一轮即第11轮结果如何,1班排球队积分最多)?若能,求出相应的概率;若不能,请说明理由.
参考数据:,则
,
,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](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/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ae7fb954b47cb67fdde891c3b9d8295.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e1d4bfe34a8831230bc974d87d05e46.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10326b41ae31356fa3379160a2efc863.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b7bc9d7251a8274049f598111cd3514.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50e110c645197c4c2a4edf582df5ae71.png)
(i)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/801ca8438513479df9afba162a7bfd74.png)
(ii)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b45d515488b2ddf9d60a439350f1bac.png)