[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f2g-GMcn9Hbk1459zYawRPqp7LFTJTKRIdkObQgyvstA":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":19,"related":20,"source":30,"type":31},[],"2025-04-15 23:33:38",183143494,[8,9,10,11],"10","15","20","25",{"count":13,"courseId":14,"courseImg":15,"courseName":16,"workId":17,"workName":18},13,"2ea5d2eeb98153c3bd18e6ea754134fb","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fd9341000627de0f431e0337a4d583c12.jpg","应用数学（2024级智能建造课程）","work_42175709","第八次作业随机变量的数字特征","已知长途汽车站每30分钟发车一次,某乘客随机到达车站,则其平均候车时间为 ( )分钟",[21,32,41,50,53,62,71,77,82,87],{"answer":22,"createTime":5,"id":23,"options":24,"question":29,"source":30,"type":31},[],183143491,[25,26,27,28],"2","2.4","2.6","2.2","若随机变量X的概率分布为:随机变量X可以取1,2,3三个值,而对应的概率为0.3,0.2,0.5则E(X)=( )","v1",0,{"answer":33,"createTime":5,"id":34,"options":35,"question":40,"source":30,"type":31},[],183143492,[36,37,38,39],"甲:乙=2:1","甲:乙=3:1","甲:乙=1:1","甲:乙=4:1","在一场赌博中,某一方先胜3局便算赢家,那么,当甲方胜了2局,乙方胜了1局的情况下,因出现意外,赌局被中断无法继续,此时,赌金的分配方案是( )(假设每局比赛甲胜出和乙胜出是相互独立的,等可能的)",{"answer":42,"createTime":5,"id":43,"options":44,"question":49,"source":30,"type":31},[],183143493,[45,46,47,48],"1\u002F3","2\u002F3","1","4\u002F3","已知随机变量X~B(1,p),且P(X=0)=1\u002F3,则随机变量X的数学期望E(X)=( )",{"answer":51,"createTime":5,"id":6,"options":52,"question":19,"source":30,"type":31},[],[8,9,10,11],{"answer":54,"createTime":5,"id":55,"options":56,"question":61,"source":30,"type":31},[],183143495,[57,58,59,60],"9.1","9.2","9.3","9.4","若X~\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Ff1f0e4133917987fff4082453f896f51.png\">,则E(X)=( )",{"answer":63,"createTime":5,"id":64,"options":65,"question":70,"source":30,"type":31},[],183143496,[66,67,68,69],"\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fe059259dfc4ddd34cbaa4bc0c8bd8f3a.webp\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fe98a8f4f69c864d2cb9ea7b5a9320bdd.webp\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Ff33bce2778d62bb4f0ed4f2596fce5a3.webp\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F632395a1e79d8f99ac8b6015ae0f06b3.webp\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F5724f08b7429306b85cde95012e88c2e.png\">,则E(X)=( )",{"answer":72,"createTime":5,"id":73,"options":74,"question":75,"source":30,"type":76},[],183143497,[],"已知一盒中有3个球(2黑1白),从中任取2球,X为2球中的白球的个数,则E(X)=( )最简分数作答",2,{"answer":78,"createTime":5,"id":79,"options":80,"question":81,"source":30,"type":76},[],183143498,[],"某投资项目有20%概率为市场销售情况好,收益为20万元,50%为市场销售情况一般,收益为5万元,30%为情况差,预计亏损8万元,则投资项目的收益期望为( )万元(小数作答)",{"answer":83,"createTime":5,"id":84,"options":85,"question":86,"source":30,"type":76},[],183143499,[],"按规定,某车站每天8:00~9:00,9:00~10:00都恰有一辆客车到站,但到站的时刻是随机的,且两者到站的时间相互独立.其规律为\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fe826db203b7ebc7a3fb5bd5b9337e2ae.png\">一旅客8:00到车站,候车时间的数学期望为______(分)",{"answer":88,"createTime":5,"id":89,"options":90,"question":91,"source":30,"type":76},[],183143500,[],"设顾客在某银行的窗口等待服务的时间X(以分计)服从指数分布,其概率密度为\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F7cefd8e89ffef7fdc3d83274d7566306.png\">因此,顾客平均等待_______分钟就可得到服务"]