名校
解题方法
1 . 已知随机变量
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93b6aa2cb8a2cf780a88c861c74794aa.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53c1ed67167078ea4f5f1ee53ee14164.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e4864bd90e67dbef62aa023e60bf58e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93b6aa2cb8a2cf780a88c861c74794aa.png)
您最近一年使用:0次
解题方法
2 . 若随机变量
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b260578876e57bd8298c45f77715566.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/221e8039aabd3cef924476edfe6c98ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e79f93023fa4c71ae88cceaefb2f0543.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b260578876e57bd8298c45f77715566.png)
您最近一年使用:0次
解题方法
3 . 已知
且
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f56a1d915caad64cdc24c16dc3c078a.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27d91dfb64f1f28c745e7a7312c3d0cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96be311667bea843a2629beba123224a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d02c257fa086cf606f941c97602606e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f56a1d915caad64cdc24c16dc3c078a.png)
您最近一年使用:0次
名校
4 . 下面给出四种说法:
①用相关指数
来刻画回归效果,
越小,说明模型的拟合效果越好;
②命题P:“
,
”的否定是¬P:“
,
”;
③设随机变量X服从正态分布
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48fe8fe0f31762c1c6063bb9d413138e.png)
④回归直线一定过样本点的中心
.
其中正确的说法有___________ (请将你认为正确的说法的序号全部填写在横线上)
①用相关指数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c85067c53e936ef32da818efe04bdbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c85067c53e936ef32da818efe04bdbb.png)
②命题P:“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02491f9709f00a1bc169278fbe01f576.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3bf2891d3042a6f18860d2361eac0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d96b743603ab1c10330622f16db78dbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/371dfe9673b7df9d53e6d0dd6ad6f20f.png)
③设随机变量X服从正态分布
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37bbde2076bfa6dd859f7787e155ab8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e73078757426543ae54d4aa30cf69390.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48fe8fe0f31762c1c6063bb9d413138e.png)
④回归直线一定过样本点的中心
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bda105ec292aac7ab1485bd5031783fb.png)
其中正确的说法有
您最近一年使用:0次
解题方法
5 . 已知随机变量
服从正态分布
,若
,且
的最小值为-3,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6424b9d168b3d2d879d7e284abf73d3.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a09dfdabc9deec16357aca1476d80c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/675116bc14a31ad4f82b4e20b8cce279.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/610aeecf367c34519560134fea370c4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6424b9d168b3d2d879d7e284abf73d3.png)
您最近一年使用:0次
解题方法
6 . 某校高二年级1200人,期末统测的数学成绩,则这次统测数学及格的人数约为(满分150分,不低于90分为及格)
(附:,
)
您最近一年使用:0次
7 . 已知随机变量
,若
,则
的取值范围是______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1290917c2c835b61384480b335cc1d13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39980d60b292af51b5f02f68e5db573e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1100379a4385b9ce064847bc21760adc.png)
您最近一年使用:0次
8 . 已知随机变量
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c306847bc11d845df15b84287899330c.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4df54f5b39a30808439a4139d2c82bf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d0d4f75f0cc6c6ce50746c716fe564.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c306847bc11d845df15b84287899330c.png)
您最近一年使用:0次
2023-06-21更新
|
122次组卷
|
2卷引用:河南省洛阳强基联盟2022-2023学年高二下学期5月联考数学试题
名校
解题方法
9 . 在一次高二数学联考中,某校数学成绩
.已知
,则从全校学生中任选一名学生,其数学成绩小于100分的概率为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3143794f5a13c28c1943a596941a6bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bbbcd9b488dcb0eef0f8b2377675a07.png)
您最近一年使用:0次
2023-06-03更新
|
419次组卷
|
3卷引用:河南省新乡市长垣市2022-2023学年高二下学期第三次联考数学试题
解题方法
10 . 已知某小麦品种的株高
(单位:
)服从正态分布
,且
,现从该品种小麦中任取2株,则这2株小麦株高都超过
的概率为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a79cefa721b69809c325ff665892680a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0834f4add762eb3f6c66dd5bf21265f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f748a2fff2648c65b80355004b13bbc.png)
您最近一年使用:0次