解题方法
1 . 某校拟举办“成语大赛”,高一(1)班的甲、乙两名同学在本班参加“成语大赛”选拔测试,在相同的测试条件下,两人
次测试的成绩(单位:分)的茎叶图如图所示.
![](https://img.xkw.com/dksih/QBM/2021/2/22/2663433729589248/2665644012781568/STEM/3815c742-d730-4cfa-a9cf-4873a783b4d4.png)
(1)你认为选派谁参赛更好?并说明理由;
(2)若从甲、乙两人
次的成绩中各随机抽取
次进行分析,设抽到的
次成绩中,
分以上的次数为
,求随机变量
的分布列和数学期望
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://img.xkw.com/dksih/QBM/2021/2/22/2663433729589248/2665644012781568/STEM/3815c742-d730-4cfa-a9cf-4873a783b4d4.png)
(1)你认为选派谁参赛更好?并说明理由;
(2)若从甲、乙两人
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a17161b28b6ad8f57abc5b11e1b6c671.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bf3baba074e8aeb6f3ea117865bbd1b.png)
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