12-13高三·吉林长春·阶段练习
1 . 给出下列5种说法:①在频率分布直方图中,众数左边和右边的直方图的面积相等;②标准差越小,样本数据的波动也越小;③回归分析就是研究两个相关事件的独立性;④在回归分析中,预报变量是由解释变量和随机误差共同确定的;⑤相关指数
是用来刻画回归效果的,
的值越大,说明残差平方和越小,回归模型的拟合效果越好. 其中说法正确的是____________ (请将正确说法的序号写在横线上).
![](https://img.xkw.com/dksih/QBM/2013/8/23/1571324149637120/1571324155011072/STEM/a59a48ce7b184f9b8f9758e0bd43029c.png?resizew=21)
![](https://img.xkw.com/dksih/QBM/2013/8/23/1571324149637120/1571324155011072/STEM/a59a48ce7b184f9b8f9758e0bd43029c.png?resizew=21)
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10-11高二下·河南郑州·期末
2 . 某医疗研究所为了检验某种血清预防感冒的作用,把
名使用血清的人与另外
名未用血清的人一年中的感冒记录作比较,提出假设
:“这种血清不能起到预防感冒的作用”,利用
列联表计算得
,经查对临界值表知
.对此,四名同学做出了以下的判断:
:有
的把握认为“这种血清能起到预防感冒的作用”
:若某人未使用该血清,那么他在一年中有
的可能性得感冒
:这种血清预防感冒的有效率为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b399e6815afcaa24f2889e58c79c10a1.png)
:这种血清预防感冒的有效率为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3e6f66f9e4e2a49a0db2489894e9d97.png)
则下列结论中,正确结论的序号是
①
; ②
; ③
; ④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821b8672d030c240ff230a0174aa7a3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821b8672d030c240ff230a0174aa7a3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e6889f68ad87503b2701245c10a1c22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b72fcdc709e77910cd36a26369648b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1c77f1ccccd5ed0722e85662121fb2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a93888a85455e51d2f0d21e34263d7b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b399e6815afcaa24f2889e58c79c10a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b399e6815afcaa24f2889e58c79c10a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b399e6815afcaa24f2889e58c79c10a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5873c01192b7d33b7483f444f90b5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3e6f66f9e4e2a49a0db2489894e9d97.png)
则下列结论中,正确结论的序号是
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97842fd0ea2ea493566e5b4e363daa5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abb9d57cbe246df4aa7b2e12e4aed9ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2a13a3d79276f22cec9a68f45a0e41f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54f1970f59d932385059964c1b160cec.png)
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9-10高一下·浙江宁波·期末
解题方法
3 . 定义:在数列
中,若
,(n≥2,n∈N*,p为常数),则称
为“等方差数列”.下列是对“等方差数列”的有关判断:
①若
是“等方差数列”,则数列
是等差数列;②
是“等方差数列”;
③若
是“等方差数列”,则数列
(k∈N*,k为常数)也是“等方差数列”;
④若
既是“等方差数列”,又是等差数列,则该数列是常数数列.
其中正确的命题为________________ .(写出所有正确命题的序号)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33c0935ed5f2d2512f53eb09df579368.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41cf1da18d91f7c98086553d157d1a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34b4dfebd3972ff16ebe879914b76291.png)
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39a561552fc52b697f1a7f1c81c2f637.png)
④若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
其中正确的命题为
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