1 . 某中学将100名高一新生分成水平相同的甲、乙两个“平行班”,每班50人.陈老师采用A、B两种不同的教学方式分别在甲、乙两个班级进行教改实验.为了解教学效果,期末考试后,陈老师对甲、乙两个班级的学生成绩进行统计分析,画出频率分布直方图(如下图).记成绩不低于90分者为“成绩优秀”
![](https://img.xkw.com/dksih/QBM/2017/7/8/1732911322865664/1790461041377280/STEM/ea3621d308e74d02b08fdfeb1c45fc82.png?resizew=418)
(1)从乙班随机抽取2名学生的成绩,记“成绩优秀”的个数为
,求
的分布列和数学期望;
(2)根据频率分布直方图填写下面2 x2列联表,并判断是否有95%的把握认为:“成绩优秀”与教学方式有关.
附:
![](https://img.xkw.com/dksih/QBM/2017/7/8/1732911322865664/1790461041377280/STEM/ea3621d308e74d02b08fdfeb1c45fc82.png?resizew=418)
![]() | 0.05 | 0.01 | 0.001 |
![]() | 3.841 | 6.635 | 10.828 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
(2)根据频率分布直方图填写下面2 x2列联表,并判断是否有95%的把握认为:“成绩优秀”与教学方式有关.
甲班(A方式) | 乙班(B方式) | 总计 | |
成绩优秀 | |||
成绩不优秀 | |||
总计 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ec635ad3b4710e261b36557fc5becde.png)
您最近一年使用:0次
2017-10-08更新
|
362次组卷
|
2卷引用:福建省数学基地校2017届高三毕业班总复习 概率与统计平行性测试数学(理)试题
2 . 下面的一组图形为一四棱锥
的侧面与底面.
![](https://img.xkw.com/dksih/QBM/2017/7/8/1732911343869952/1790904252096512/STEM/84f724c722d34652b7613f924ddac8af.png?resizew=549)
(I)请画出四棱锥
的示意图,是否存在一条侧棱垂直于底面?如果存在的话,指出是示意图中的哪一条,说明理由.
(II)若![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6e2867f32d3f1c3cd36cd3a11a8580.png)
面
,
为
中点,求证:面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73f7e6fc8324f9f7f826677be25a6479.png)
面
;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://img.xkw.com/dksih/QBM/2017/7/8/1732911343869952/1790904252096512/STEM/84f724c722d34652b7613f924ddac8af.png?resizew=549)
(I)请画出四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
(II)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6e2867f32d3f1c3cd36cd3a11a8580.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73f7e6fc8324f9f7f826677be25a6479.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ef796b46e68fe77b117ff0483d2370c.png)
您最近一年使用:0次