【单选题】【消耗次数：1】
20只大鼠按照体重随机分成10对，进行配对t检验，则自由度为：
①
20
②
19
③
10
④
9
参考答案：
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相关题目
【单选题】
已知四点A（10、20、30）、B（30、20、10）、C（10、20、10）、D（20、20、30），则对H面的重影点为______。
①
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
A与D，D点可见
②
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
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mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
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mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
B与C，B点可见
③
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
A与C，A点可见
④
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
A与C，C点可见
【单选题】
A点坐标为（10、20、30），B点坐标为（30、20、30）则AB距离为______。
①
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
正垂线
②
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
侧垂线
③
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:等线;
mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
正平线
④
Normal
0
7.8 磅
0
2
false
false
false
EN-US
ZH-CN
X-NONE
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:普通表格;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-parent:"";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
mso-para-margin:0cm;
mso-para-margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:10.5pt;
mso-bidi-font-size:11.0pt;
font-family:等线;
mso-ascii-font-family:等线;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:等线;
mso-fareast-theme-font:minor-fareast;
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mso-hansi-theme-font:minor-latin;
mso-font-kerning:1.0pt;}
铅垂线
随机题目
【单选题】
若<imgwidth="14"height="16"v:shapes="_x0000_i1178"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image188.png">阶可逆矩阵<imgwidth="18"height="18"v:shapes="_x0000_i1179"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image189.png">与<imgwidth="18"height="18"v:shapes="_x0000_i1180"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image190.png">相似，且<imgwidth="56"height="22"v:shapes="_x0000_i1181"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image192.png">则<imgwidth="40"height="22"v:shapes="_x0000_i1182"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image194.png">（）
①
<imgwidth="30"height="18"v:shapes="_x0000_i1183"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image196.png">
②
<imgwidth="28"height="18"v:shapes="_x0000_i1184"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image198.png">
③
<imgwidth="18"height="18"v:shapes="_x0000_i1185"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image190.png">
④
<imgwidth="26"height="22"v:shapes="_x0000_i1186"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds05.files/image201.png">
【单选题】
设<imgwidth="83"height="25"v:shapes="_x0000_i1163"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image233.png">则下列式中不成立的是（）
①
<imgwidth="46"height="21"v:shapes="_x0000_i1164"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image235.png">
②
<imgwidth="49"height="21"v:shapes="_x0000_i1165"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image237.png">
③
<imgwidth="84"height="27"v:shapes="_x0000_i1166"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image239.png">
④
<imgwidth="87"height="41"v:shapes="_x0000_i1167"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb09.files/image241.png">
【单选题】
设随机变量X的分布函数为<imgwidth="36"height="21"v:shapes="_x0000_i1107"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image108.png">，下列结论中不一定成立的是（）
①
<imgwidth="69"height="21"v:shapes="_x0000_i1108"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image132.png">
②
<imgwidth="73"height="21"v:shapes="_x0000_i1109"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image134.png">
③
<imgwidth="80"height="21"v:shapes="_x0000_i1110"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image136.png">
④
<imgwidth="36"height="21"v:shapes="_x0000_i1111"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image108.png">为连续函数
【单选题】
<imgwidth="14"height="16"v:shapes="_x0000_i1251"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image293.png">阶实对称矩阵<imgwidth="18"height="18"v:shapes="_x0000_i1252"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image285.png">的<imgwidth="14"height="16"v:shapes="_x0000_i1253"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image293.png">个行向量是一组正交单位向量组，则<imgwidth="18"height="18"v:shapes="_x0000_i1254"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image285.png">是（）
①
对称矩阵
②
正交矩阵
③
反对称矩阵
④
<imgwidth="54"height="22"v:shapes="_x0000_i1255"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image329.png">
【单选题】
<imgwidth="432"height="27"v:shapes="图片_x0020_193"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image199.png">
①
<imgwidth="185"height="33"v:shapes="图片_x0020_194"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image200.png">
②
<imgwidth="176"height="32"v:shapes="图片_x0020_195"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image201.png">
③
<imgwidth="455"height="29"v:shapes="图片_x0020_196"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image202.png">
④
<imgwidth="289"height="26"v:shapes="图片_x0020_197"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds02.files/image203.png">
【单选题】
设随机变量X的概率密度函数为<imgwidth="36"height="21"v:shapes="_x0000_i1112"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image139.png">，且<imgwidth="88"height="27"v:shapes="_x0000_i1113"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image141.png">，则必有（）
①
<imgwidth="36"height="21"v:shapes="_x0000_i1114"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image139.png">在<imgwidth="50"height="27"v:shapes="_x0000_i1115"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image144.png">内大于零
②
<imgwidth="36"height="21"v:shapes="_x0000_i1116"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image139.png">在<imgwidth="50"height="27"v:shapes="_x0000_i1117"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image147.png">内小于零
③
<imgwidth="90"height="35"v:shapes="_x0000_i1118"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image149.png">
④
<imgwidth="36"height="21"v:shapes="_x0000_i1119"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image139.png">在<imgwidth="50"height="27"v:shapes="_x0000_i1120"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb07.files/image144.png">上单调增加
【单选题】
设<imgwidth="18"height="18"v:shapes="_x0000_i1383"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image008.png">为<imgwidth="14"height="16"v:shapes="_x0000_i1384"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image293.png">阶方阵，则（）不成立
①
若<imgwidth="18"height="18"v:shapes="_x0000_i1385"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image008.png">可逆，而矩阵<imgwidth="18"height="18"v:shapes="_x0000_i1386"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image008.png">的属于特征值<imgwidth="16"height="20"v:shapes="_x0000_i1387"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image491.png">的特征向量也是矩阵<imgwidth="28"height="22"v:shapes="_x0000_i1388"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image493.png">属于特征值<imgwidth="19"height="42"v:shapes="_x0000_i1389"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image495.png">的特征向量
②
<imgwidth="18"height="18"v:shapes="_x0000_i1390"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image008.png">的全部特征向量即为方程<imgwidth="106"height="24"v:shapes="_x0000_i1391"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image497.png">的全部解
③
若<imgwidth="18"height="18"v:shapes="_x0000_i1392"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image498.png">存在属于特征值<imgwidth="16"height="17"v:shapes="_x0000_i1393"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image499.png">的<imgwidth="14"height="16"v:shapes="_x0000_i1394"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image004.png">个线性无关的特征向量，则<imgwidth="56"height="20"v:shapes="_x0000_i1395"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image501.png">
④
<imgwidth="18"height="18"v:shapes="_x0000_i1396"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image008.png">与<imgwidth="26"height="22"v:shapes="_x0000_i1397"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image503.png">有相同的特征值
【单选题】
两个独立事件A和B发生的概率分别为<imgwidth="19"height="25"v:shapes="_x0000_i1029"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image010.png">和<imgwidth="20"height="25"v:shapes="_x0000_i1030"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image012.png">，则其中之一发生的概率为（）
①
<imgwidth="49"height="25"v:shapes="_x0000_i1031"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image014.png">
②
<imgwidth="67"height="25"v:shapes="_x0000_i1032"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image016.png">
③
<imgwidth="67"height="25"v:shapes="_x0000_i1033"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image018.png">
④
<imgwidth="140"height="25"v:shapes="_x0000_i1034"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image020.png">
【单选题】
<imgwidth="415"height="29"v:shapes="图片_x0020_156"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds01.files/image154.png">
①
<imgwidth="57"height="28"v:shapes="图片_x0020_157"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds01.files/image155.png">
②
<imgwidth="109"height="29"v:shapes="图片_x0020_158"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds01.files/image156.png">
③
<imgwidth="107"height="23"v:shapes="图片_x0020_159"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds01.files/image157.png">
④
<imgwidth="121"height="31"v:shapes="图片_x0020_160"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds01.files/image158.png">
【单选题】
<imgwidth="361"height="296"v:shapes="_x0000_i1281"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image439.png">
①
<imgwidth="21"height="41"v:shapes="_x0000_i1282"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image441.png">
②
<imgwidth="21"height="41"v:shapes="_x0000_i1283"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image443.png">
③
<imgwidth="21"height="41"v:shapes="_x0000_i1284"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image445.png">
④
<imgwidth="21"height="41"v:shapes="_x0000_i1285"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb08.files/image447.png">