题目描述
<p class="MsoListParagraph" style="margin-left:18.0pt;text-indent:0cm;"> 某班级的一次考试由两次测试组成,<span>X</span>、<span>Y</span>分别表示一名学生第一次、第二次测试的成绩,已知<span>X</span>、<span>Y</span>的联合分布律如下表<span></span> </p> <p class="MsoListParagraph" style="margin-left:18.0pt;text-indent:0cm;"> <span> </span> </p> <table class="MsoTableGrid" border="1" cellspacing="0" cellpadding="0" style="border:none;"> <tbody> <tr> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>Y X</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>5</span> </p> </td> <td width="92" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>10</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>15</span> </p> </td> </tr> <tr> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.02</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.06</span> </p> </td> <td width="92" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span> 0.02</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.10</span> </p> </td> </tr> <tr> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>5</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.04</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.15</span> </p> </td> <td width="92" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.20</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.10</span> </p> </td> </tr> <tr> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>10</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.01</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.15</span> </p> </td> <td width="92" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.14</span> </p> </td> <td width="106" valign="top" style="border:solid windowtext 1.0pt;"> <p class="MsoListParagraph" style="text-indent:0cm;"> <span>0.01</span> </p> </td> </tr> </tbody> </table> <p class="MsoListParagraph" style="margin-left:18.0pt;text-indent:0cm;"> <span> <p class="MsoListParagraph" style="margin-left:54.0pt;text-indent:-36.0pt;"> <span>(1) </span>若规定这次考试的成绩为两次测试的最大值,即<span>Z1=max{X,Y}</span>,求<span>E[max{X,Y}]</span> </p> <p class="MsoListParagraph" style="margin-left:54.0pt;text-indent:-36.0pt;"> <span>(2) </span>若规定这次考试的成绩为两次测试之和,即<span>Z2=X+Y</span>,求<span>E(X+Y)</span>。<span></span> </p> </span> </p>
输入格式
<p class="MsoListParagraph" style="margin-left:54.0pt;text-indent:0cm;"> 每小题输入题号,<span>1</span>或者<span>2 </span>,请输出对应结果,保留一位小数。<span></span> </p> <p class="MsoListParagraph" style="margin-left:54.0pt;text-indent:0cm;"> <span> 0</span> </p>
输出格式
0.1
样例
样例输入 1
0
样例输出 1
0.1
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