20春学期《概率论X》在线平时作业2

adminhan

&nbsp;&nbsp;<div>&nbsp;设随机变量X服从正态分布N（u₁，<span>&sigma;₁² )，随机变量Y服从正态分布N（u₂，<span>&sigma;₂² )，且P{|X-u₁|&lt;1}&gt;P{|Y-u₂|&lt;1}，则有（）</span></span></div>
A:<span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Arial','sans-serif'; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">&sigma;₁&lt;<span style="WORD-SPACING: 0px; FLOAT: none; ORPHANS: 2; WIDOWS: 2; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">&sigma;₂</span></span>
B:<span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Arial','sans-serif'; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">&sigma;₁&gt;<span style="WORD-SPACING: 0px; FLOAT: none; ORPHANS: 2; WIDOWS: 2; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">&sigma;₂</span></span>
C:^{<span lang="EN-US" style="FONT-SIZE: 13.5pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">u1&lt;u2</span>}
D:<div>u1&gt;u2</div>

从中心极限定理可以知道：
A:抽签的结果与顺序无关；
B:二项分布的极限分布可以是正态分布；
C:用频率的极限来定义随机事件的概率是合理的；
D:独立的正态随机变量的和仍然服从正态分布。

<span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">设</span><span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">X</span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">是一随机变量，</span><span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">E</span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">（</span><span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">X</span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">）</span><span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">=u</span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">，</span><span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">D(x)=</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Arial','sans-serif'; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">&sigma;²</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">（</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Arial','sans-serif'; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">u,&sigma;&gt;0</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">常数），则对任意常数</span><span lang="EN-US" style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Arial','sans-serif'; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">c</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">，必有</span><span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Arial','sans-serif'; BACKGROUND: white; COLOR: black; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体"> </span>
A:<span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">E</span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">（</span><span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">X-c</span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-family: Arial; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">）</span>^{<span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">2</span>}<span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: 'Arial','sans-serif'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">=E(X²)-c²</span>
B:E(X-c)²=E(X-u)^2&nbsp;
C:<span>^&nbsp;</span>E(X-c)²&lt;E(X-u)^2&nbsp;
D:<div>^&nbsp;E(X-c)²&gt;=E(X-u)²</div>

从1~2000的整数中随机地抽取1个数，则这个数能被10整除的概率是
A:1|5
B:1|10
C:1|20
D:1|30

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">设随机变量X</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">与</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US"><span style="POSITION: relative; TOP: 2pt; mso-text-raise: -2.0pt"></span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">Y相互独立,X</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">服从&ldquo;</span><strong style="mso-bidi-font-weight: normal"><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">0<st1:chmetcnv w:st="on" unitname="”" sourcevalue="1" hasspace="False" negative="True" numbertype="1" tcsc="0">-1<span style="FONT-FAMILY: 宋体; FONT-WEIGHT: normal; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'" lang="EN-US"><span lang="EN-US">&rdquo;</span></span></st1:chmetcnv><span style="FONT-FAMILY: 宋体; FONT-WEIGHT: normal; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'" lang="EN-US">分布,p=0.4；Y</span></span></strong><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">服从</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US"><span style="POSITION: relative; TOP: 3pt; mso-text-raise: -3.0pt"></span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt"><span style="WIDOWS: 2; TEXT-TRANSFORM: none; BACKGROUND-COLOR: rgb(255,255,255); TEXT-INDENT: 30px; DISPLAY: inline !important; FONT: 14px/24px arial, 宋体, sans-serif; WHITE-SPACE: normal; ORPHANS: 2; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(0,0,0); WORD-SPACING: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">&lambda;=2</span>的泊松分布</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US"><span style="POSITION: relative; TOP: 5pt; mso-text-raise: -5.0pt"></span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">，则E(X+Y)=</span>
A:0.8
B:1.6
C:2.4
D:2

如果随机事件A，B相互独立，则有：
A:AB=空集；
B:P(A)=P(B)；
C:P(A|B)=P(A)；
D:AB=B。

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">设随机变量</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">X</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">与</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">Y</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">服从正态分布，</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">X~N</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">（</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">u</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">，</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">4²</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">），</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">Y~N</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">（</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">u,5²),</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">记</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">P₁⁼P{X&lt;=u-4}</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">，</span><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体" lang="EN-US">P₂=P{X&gt;=u+5}</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial">，则（）</span>
A:<div>对任意数u，都有P1=P2</div>
B:只有u的个别值才有P1=P2
C:<div>对任意实数u，都有P1&lt;P2</div>
D:<div>对任意实数u，都有P1&gt;P2</div>

卖水果的某个体户，在不下雨的日子可赚100元，在雨天则要损失10元。该地区每年下雨的日子约有130天，则该个体户每天获利的期望值是（1年按365天计算）
A:90元
B:45元
C:55元
D:60.82元

设随机变量X和Y的相关系数为0.9，若Z=X-0.4，则Y与Z的相关系数为
A:0.1
B:-0.1
C:0.9
D:-0.9

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">已知随机变量</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">X</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">服从正态分布</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">N</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">（</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">，</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">2²</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">）且</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">Y=aX+b</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">服从标准正态分布，则</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"> </span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">（</span><span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp; </span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">）</span>
A:<span style="FONT-FAMILY: &quot;Times New Roman&quot;; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">a = 2 , b = -2<span style="mso-spacerun: yes">&nbsp; </span></span>
B:<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">a = -2 , b = -1</span>
C:<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">a = 1/2 , b = -1</span>
D:<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 9pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">a = 1/2 , b = 1</span>

设随机变量X~N（2，4），且P{2&lt;X&lt;4}=0.3，则P{X&lt;0}=（）
A:0.8
B:0.2
C:0.5
D:0.4

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">若P(A)=0,B</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">为任一事件，则</span>
A:A为空集
B:B包含A
C:<p>A,B相互独立</p>
D:A,B互不相容

<p>设F₁（x）与F₂（x）分别为随机变量X₁与X₂的分布函数。为使F(x)=aF₁(x)-bF₂(x)是某一随机变量的分布函数，在下列给定的各组数值中应取（）</p>
A:a=3/5, b=-2/5
B:a=2/3, b=2/3
C:a=-1/2, b=3/2
D:a=1/2, b=-3/2

从1~100共100个正整数中，任取1数，已知取出的1数不大于50，求此数是2的倍数的概率：
A:<p>0.3</p>
B:0.4
C:0.5
D:0.6

<p style="TEXT-INDENT: 10.5pt; MARGIN: 0cm 0cm 0pt; mso-char-indent-count: 1.0" class="MsoNormal"><font size="3"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">设随机变量</span><span lang="EN-US"><font face="Times New Roman">X</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">服从正态分布</span><span lang="EN-US"><font face="Times New Roman">X~N</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">（</span><span lang="EN-US"><font face="Times New Roman">0</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，</span><span lang="EN-US"><font face="Times New Roman">1），</font></span><span lang="EN-US"><font face="Times New Roman">Y=2X-1</font></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，则</span><span lang="EN-US"><font face="Times New Roman">Y~<span style="mso-spacerun: yes">&nbsp;</span></font></span></font></p>
A:<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">N</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">0</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">，</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">1</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">）</span>
B:<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">N</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">-1</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">，</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">4</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">）</span>
C:<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">N</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">-1</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">，</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">1</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">）</span>
D:<span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">N</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">（</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">-1</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">，</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">3</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">）</span>

独立地抛掷一枚质量均匀硬币，已知连续出现了10次反面，问下一次抛掷时出现的是正面的概率是：
A:1/11
B:B.1/10
C:C.1/2
D:D.1/9

下面哪个条件不能得出两个随机变量X与Y的独立性？
A:联合分布函数等于边缘分布函数的乘积；
B:如果是离散随机变量，联合分布律等于边缘分布律的乘积；
C:如果是连续随机变量，联合密度函数等于边缘密度函数的乘积；
D:乘积的数学期望等于各自期望的乘积：E(XY)=E(X)E(Y)。

<img alt="" src="http://file.open.com.cn/itemdb/dbdx/gailvlun/test/12313281440781.3.jpg" />&nbsp;
A:1/3和1/2
B:2/3和1/2
C:1/2和1/2
D:1/6和1/6

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">将<span lang="EN-US">10</span>个球依次从<span lang="EN-US">1</span>至<span lang="EN-US">10</span>编号后置入袋中，任取两球，二者号码之和记为<span lang="EN-US">X,则P（X小于等于18）=</span></span>
A:<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US"><span style="mso-spacerun: yes">&nbsp;</span>43/45</span>
B:<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">44/45</span>
C:<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">72/100</span>
D:<p>64/100</p>

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-no-proof: yes">袋中有<span lang="EN-US">50</span>个乒乓球，其中<span lang="EN-US">20</span>个黄的，<span lang="EN-US">30</span>个白的，现在两个人不放回地依次从袋中随机各取一球。则第二人取到黄球的概率是</span>
A:<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-no-proof: yes" lang="EN-US">1/5 </span>
B:2/5
C:3/5
D:4/5

从装有3个红球和2个白球的袋子中任取两个球，记A=&ldquo;取到两个白球&rdquo;，则<img alt="" src="http://file.open.com.cn/itemdb/dbdx/gailvlun/test/1.jpg" />=
A:取到两个红球
B:至少取到一个白球
C:没有一个白球
D:至少取到一个红球

<p>随机变量X~N（1,4），且P（X&lt;2）=0.6，则P(X&lt;-2)=</p>
A:0.3
B:0.4
C:0.5
D:0.6

设两个随机变量X和Y的期望分别是6和3，则随机变量2X－3Y的期望是
A:6
B:3
C:12
D:21

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">设两个相互独立的随机变量X</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">和</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US"><span style="POSITION: relative; TOP: 2pt; mso-text-raise: -2.0pt">Y</span></span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">的方差分别为</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">4</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">和</span><span style="FONT-FAMILY: 'Times New Roman'; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt" lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-bidi-font-size: 12.0pt">，则随机变量3X-2Y的方差为（）</span>
A:44
B:8
C:28
D:32

<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">事件<span lang="EN-US">A</span>与<span lang="EN-US">B</span>相互独立的充要条件为</span>
A:<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">A+B=U</span>
B:<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">P(AB)=P(A)P(B）</span>
C:A,B的交集为空集
D:<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-bidi-font-family: 'Times New Roman'; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" lang="EN-US">P(A+B)=P(A)+P(B)</span>

主观概率指的是对于不能做重复试验的随机事件，人们各自给出的对这个事件发生的相信程度。
A:错误
B:正确

利用一个随机事件的频率(比例)能够求出概率的一个精确值。
A:错误
B:正确

如果变量X服从均值是m，标准差是s的正态分布，则z=(X－m)/s服从标准正态分布。
A:错误
B:正确

抛一个质量均匀的硬币n次，正面出现n/2次的概率最大。
A:错误
B:正确

利用等可能性计算概率需满足的条件是，实验的所有可能结果数是已知的，且每种实验结果出现的可能性一样。
A:错误
B:正确