全国2013年10月高等教育自学考试
概率论与数理统计(经管类)试题
课程代码:04183
一、单项选择题(本大题共10小题,每小题2分,共20分)
在每小题列出的四个备选项中只有一个是符合题目要求的,请将其选出并将“答题纸”的相应代码涂黑。错涂、多涂或未涂均无分。
1.设A,B为随机事件,则事件“A,B至少有一个发生”可表示为
A.AB B.
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C.
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D.
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2.设随机变量
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,Φ
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为标准正态分布函数,则
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=
A.Φ(x) B.1-Φ(x)
C.Φ
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D.1-Φ
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3.设二维随机变量
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,则X~
A.
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B.
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C.
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D.
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4.设二维随机变量(X,Y)的分布律为
且
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,则
A. a=0.2, b=0.4 B. a=0.4, b=0.2
C. a=0.1, b=0.5 D. a=0.5, b=0.1
5.设随机变量
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,且

=2.4,

=1.44,则
A. n=4, p=0.6 B. n=6, p=0.4
C. n=8, p=0.3 D. n=24, p=0.1
6.设随机变量
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,Y服从参数为
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的指数分布,则下列结论中不正确的是
A.
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B.
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C.
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D.
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7.设总体X服从[
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]上的均匀分布(参数
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未知),
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为来自X的样本,则下列随机变量中是统计量的为
A.
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B.
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C.
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D.
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8.设
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是来自正态总体
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的样本,其中
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未知,
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为样本均值,则
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的无偏估计量为
A.
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2 B.
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2
C.
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2 D.
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2
9.设H0为假设检验的原假设,则显著性水平
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等于
A.P{接受H0|H0不成立} B. P{拒绝H0|H0成立}
C. P{拒绝H0|H0不成立} D. P{接受H0|H0成立}
10.设总体
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,其中
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未知,
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为来自X的样本,
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为样本均值,s为样本标准差.在显著性水平
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下检验假设
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.令
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,则拒绝域为
A.
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B.
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C.
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D.
二、填空题(本大题共15小题,每小题2分,共30分)
11.设随机事件A与B相互独立,且
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,则
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=______.
12.甲、乙两个气象台独立地进行天气预报,它们预报准确的概率分别是0.8和0.7,则在一次预报中两个气象台都预报准确的概率是________.
13.设随机变量X服从参数为1的指数分布,则

=__________.
14.设随机变量

,则Y的概率密度

=________.
15.设二维随机变量(X,Y)的分布函数为

,则

=_________.
16.设随机变量X与Y相互独立,且都服从参数为1的泊松分布,则
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_______.
17.设随机变量X服从区间[0,2]上的均匀分布,则

=_______.
18.设随机变量X与Y的协方差
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,则
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=________.
19.设随机变量
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相互独立,
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,则

=________.
20.设X为随机变量,
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,则由切比雪夫不等式可得
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______.
21.设总体
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,
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为来自X的样本,则
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_________.
22.设随机变量

,且
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,则
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=_________.
23.设总体
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是来自X的样本.
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都是
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的估计量,则其中较有效的是_______.
24.设总体
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,其中
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已知,
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为来自X的样本,
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为样本均值,则对假设
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应采用的检验统计量的表达式为_______.
25.依据样本
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得到一元线性回归方程
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为样本均值,令
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2,
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,则回归常数

=________.
三、计算题(本大题共2小题,每小题8分,共16分)
26.设二维随机变量

的概率密度为

求:(1)

关于X,Y的边缘概率密度

;(2)

.
27.假设某校数学测验成绩服从正态分布,从中抽出20名学生的分数,算得样本标准差s=4分,求正态分布方差

的置信度为98%的置信区间.
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,
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四、综合题(本大题共2小题,每小题12分,共24分)
28.设某人群中患某种疾病的比例为20%.对该人群进行一种测试,若患病则测试结果一定为阳性;而未患病者中也有5%的测试结果呈阳性.
求:(1)测试结果呈阳性的概率;(2)在测试结果呈阳性时,真正患病的概率.
29.设随机变量X的概率密度为

求:(1)常数c;(2)X的分布函数
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;(3)
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.
五、应用题(10分)
30.某保险公司有一险种,每个保单收取保险费600元,理赔额10000元,在有效期内只理赔一次.设保险公司共卖出这种保单800个,每个保单理赔概率为0.04.
求:(1)理赔保单数的分布律;(2)保险公司在该险种上获得的期望利润.
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