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解题方法
1 . 某单位为患病员工集体筛查新型流感病毒,需要去某医院检验血液是否为阳性,现有
份血液样本,有以下两种检验方案,方案一:逐份检验,则需要检验k次;方案二:混合检验,将k份血液样本分别取样混合在一起检验一次,若检验结果为阴性,则k份血液样本均为阴性,若检验结果为阳性,为了确定k份血液中的阳性血液样本,则对k份血液样本再逐一检验.逐份检验和混合检验中的每一次检验费用都是
元,且k份血液样本混合检验一次需要额外收
元的材料费和服务费.假设在接受检验的血液样本中,每份样本是否为阳性是相互独立的,且据统计每份血液样本是阳性的概率为
.
(1)若
份血液样本采用混合检验方案,需要检验的总次数为X,求X分布列及数学期望;
(2)①若
,以检验总费用为决策依据,试说明该单位选择方案二的合理性;
②若
,采用方案二总费用的数学期望低于方案一,求k的最大值.
参考数据:
,
,
,
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1111bfe3526b3555b2aa57fbdb48ff97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70444e3a66d1068038c5b5a77c7954aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5bffe9674e4b3f9a4133112528adc07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29c8578f06897aa6fb84aa95c797d3d8.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fee8937927d074628df8022fce45fd9f.png)
(2)①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6d51fe9d3fbd6229532570ff018a3cc.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bb43f55430109bd9da649c8e4beb1a2.png)
参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c8f8d3d05cc8ec8771e19c950b503f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56cd9fd1bf71d7bb19b29d9d326b73a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/186edcab73f08a13fa491f884dbc13f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eca4bfa7b7b2105cf0e5e11d89e3707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3589d9db7fa446142fbcfe92a83a87ad.png)
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2020-08-14更新
|
2805次组卷
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7卷引用:安徽省合肥市第一中学2020届高三下学期最后一卷数学(理)试题
安徽省合肥市第一中学2020届高三下学期最后一卷数学(理)试题河南省南阳市2020-2021学年高三上学期期末数学(理)试题(已下线)第51讲 概率与统计综合问题-2022年新高考数学二轮专题突破精练河北省部分重点中学2022届高三下学期期中数学试题(已下线)专题11-2 概率与分布列大题归类-1(已下线)模块十 计数原理与统计概率-2(已下线)专题9-1 概率与统计及分布列归类(理)(讲+练)-2
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2 . 据长期统计分析,某货物每天的需求量
在17与26之间,日需求量
(件)的频率
分布如下表所示:
已知其成本为每件5元,售价为每件10元.若供大于求,则每件需降价处理,处理价每件2元.假设每天的进货量必需固定.
(1)设每天的进货量为
,视日需求量
的频率为概率
,求在每天进货量为
的条件下,日销售量
的期望值
(用
表示);
(2)在(1)的条件下,写出
和
的关系式,并判断
为何值时,日利润的均值最大?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5673c6c7d621d2bd796075ce3e9f79e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47604ac99dccad8aa10499f45bd26ea9.png)
需求量![]() | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |
频率![]() | 0.12 | 0.18 | 0.23 | 0.13 | 0.10 | 0.08 | 0.05 | 0.04 | 0.04 | 0.03 |
已知其成本为每件5元,售价为每件10元.若供大于求,则每件需降价处理,处理价每件2元.假设每天的进货量必需固定.
(1)设每天的进货量为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba48ec28c1cc5aa8a820a02c10c59340.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78688bda700e371428f37c922590d674.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af4207de9aa23b95a7acf2bc2d16398b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93d0f3799612b81e85b87241ec8eee68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/176f249595624605402d8cb1bcb4eae2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dafc9718739fd25c9c459cf20785800.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59c709117ab1d3ef620883a732aed68b.png)
(2)在(1)的条件下,写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dafc9718739fd25c9c459cf20785800.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abfdd5635e40dd478af6f8784d0912e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93d0f3799612b81e85b87241ec8eee68.png)
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3 . 已知函数
.
(1)指出
的单调区间;(不要求证明)
(2)若
满足
,且
,求证:
;
(3)证明:当
时,不等式
对任意
恒成立.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3e36e6158c7da6ebbf95da58658a998.png)
(1)指出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cad5124201a1776222070104ceb306c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/804c5ac86fac689aa1102df1cefafc7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4a68f76d4feecadef02aa09a084f75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd69d26f76d5a55cf072fa49b53d437.png)
(3)证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48adb8a59b5c02fad5eada1b35171cf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7b7667435fbb850e751297135b5725a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d6f67a296f5790649068d2441d5bb98.png)
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4 . 已知
,
N*,满足
,则所有数对
的个数是____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e1f5facca1d0db44613d7c690bc90aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b88021eed5e7a7fb5f8d66fa1bd937bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0203b006524305c3d8ee0b6c34cd872b.png)
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5 . 设
,
,
,将
的最小值记为
.则当
是偶数时,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7978d7bd6f6caf9ac9837ffce5f89654.png)
__________ ;当
是奇数时,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7978d7bd6f6caf9ac9837ffce5f89654.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba8ae469587300aece24a0599a630c2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36ff741c0506b0619fe6c7b1990013af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7978d7bd6f6caf9ac9837ffce5f89654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7978d7bd6f6caf9ac9837ffce5f89654.png)
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6 . 杨辉三角,又称帕斯卡三角,是二项式系数在三角形中的一种几何排列.在我国南宋数学家杨辉所著的《详解九章算法》一书中用如图所示的三角形解释二项展开式的系数规律.现把杨辉三角中的数从上到下,从左到右依次排列,得数列:
.记作数列
,若数列
的前
项和为
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57e8149e93e8622a109580970db5abfd.png)
___ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/154febe3c6f31577c39ddc619450c6c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57e8149e93e8622a109580970db5abfd.png)
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7 . 已知
(
且
,
).
(1)设
,求
中含
项的系数;
(2)化简:
;
(3)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dacd62755047aa73baeb8025df122be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38f0e9c04402a0ffdaa25c3e3c82c7dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31be670d32e753012125c503f2f3be56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f22803ceb04e55261b8416f7c823864b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be1ce3f01e2b6364f9a9fdaf197d5e29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d800f03de80068a1172beac3a2c75587.png)
(2)化简:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa4382b9c757f0157f0938959edd4901.png)
(3)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3322f0b4d3bea41d30f8ac2fc0a750fd.png)
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2019-04-29更新
|
1217次组卷
|
4卷引用:【校级联考】江苏省无锡市江阴四校2018-2019学年高二下学期期中考试数学(理)试题
8 . 设整数数列{an}共有2n(
)项,满足
,
,且
(
).
(1)当
时,写出满足条件的数列的个数;
(2)当
时,求满足条件的数列的个数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/484945dc28f9e331cd12e19e2abf4e8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9cedb02089fef906e1a51376be754fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92fb991597719e079f62b3ab64fcb458.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e76bd4c49bf39a8b627df70e6adf866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/772500049d431f5a20c43e37cf9a518c.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/561cdfac20ab4159bc7740a680595d15.png)
您最近一年使用:0次
2019-03-22更新
|
1197次组卷
|
3卷引用:【校级联考】江苏省南通市基地学校2019届高三3月联考数学试题