1 . 某中学举行了一次“垃圾分类知识竞赛”,全校学生参加了这次竞赛,为了了解本次竞赛成绩情况,从中抽取了部分学生的成绩x(单位:分,得分取正整数,满分为100分)作为样本进行统计将成绩进行整理后,分为五组(
,
,
,
,
),其中第4组,第1组,第2组的频数依次成等比数列,请根据下面尚未完成的频率分布直方图(如图所示)解决下列问题:
(2)若根据这次成绩,学校准备淘汰80%的同学,仅留20%的同学进入下一轮竞赛请问晋级分数线划为多少合理?
(3)某老师在此次竞赛成绩中抽取了10名学生的分数:
,
,
,…,
,已知这10个分数的平均数
,标准差
,若剔除其中的95和85两个分数,求剩余8个分数的平均数与方差.(附:方差计算公式:
或
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e561d9fac7ba8c70dfa731c23993682.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4257b8939a4f0c809129cbf202416397.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/273e1ca083d8248e72e9fbd2f8403db6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0aeaf113764abb5769616efecf0c7498.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fd6398a2768bade390cd738a5f1ba82.png)
(2)若根据这次成绩,学校准备淘汰80%的同学,仅留20%的同学进入下一轮竞赛请问晋级分数线划为多少合理?
(3)某老师在此次竞赛成绩中抽取了10名学生的分数:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ab84c3fe70da38ccb246fd4a71f9d86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03a9c5679255d4ee685c7135ff245fff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c11defc68a99af26bb24296ec1bf8b66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16c4d2508b9bb2560cee557ef6b6d908.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/758be7201eba213e319849ecb71d0525.png)
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2024-01-23更新
|
408次组卷
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5卷引用:内蒙古自治区锡林郭勒盟2023-2024学年高二上学期期末教学质量检测数学试卷
内蒙古自治区锡林郭勒盟2023-2024学年高二上学期期末教学质量检测数学试卷(已下线)第九章 统计(单元重点综合测试)--单元速记·巧练(人教A版2019必修第二册)(已下线)专题9.3 统计图的相关运算大题专项训练-举一反三系列(人教A版2019必修第二册)(已下线)专题23 统计图表 用样本估计总体-《重难点题型·高分突破》(苏教版2019必修第二册)(已下线)专题02 高一下期末真题精选(2)-期末考点大串讲(人教A版2019必修第二册)
2 . 已知正项等比数列
的前5项和为242,且数列
的前5项和为
,则
( )
![](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/bb2429fde35ba7dcb204ad322f5c20c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbfc875ca919921e8f63a6fca648561b.png)
A.12 | B.15 | C.16 | D.18 |
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3 . 已知
为等比数列,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbfc875ca919921e8f63a6fca648561b.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/366dfedff1a1a96ec27650375b680059.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41f7a93abb889ddc4fb67a687efeb0c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbfc875ca919921e8f63a6fca648561b.png)
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解题方法
4 . 若
是函数
的两个不同的零点,且
这三个数在适当排序后成等差数列,也在适当排序后成等比数列,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b15bd315b801f71bc30b8d772098614.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b07a00d2e9126ce823edbf60566dff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/472bc22e1d2721181e86eabad01d7a4e.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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5 . 已知等差数列
满足
,且
成等比数列.
(1)求
的通项公式;
(2)记
为数列
前
项的乘积,若
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/557b44c164dd2cefce5cef8ac40c957b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c2bd43cc4343b114769b34abf477081.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/179513ce80436471efbe1d9b31735f7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
2023-11-17更新
|
1360次组卷
|
7卷引用:内蒙古鄂尔多斯市西四旗2024届高三上学期期末综合模拟数学(文)试题
内蒙古鄂尔多斯市西四旗2024届高三上学期期末综合模拟数学(文)试题(已下线)模块五 专题2 期末全真模拟(基础卷2)高二期末浙江省绍兴市2023-2024学年高三上学期11月选考科目诊断性考试数学试题重庆市荣昌中学校2024届高三上学期第二次月考数学试题(已下线)专题6.1 等差数列及其前n项和【九大题型】(已下线)黄金卷03(已下线)专题05 数列
解题方法
6 . 已知等差数列
的公差不为零,
,且
,
,
成等比数列.
(1)求
的通项公式;
(2)求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6be3f864d60fc147b6905979403f3b2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e84c30444f13d37ada78285dc4f83b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eca7e7b23fd74e3cf89ac541cb7a5d88.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba80577ba05aeeef885884f444ba1e0d.png)
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解题方法
7 . 记
为数列
的前
项和.已知
.
(1)求
及
;
(2)记
,数列
的前
项和为
,是否存在正整数
,使得
成等比数列?若存在,求出所有满足条件的
;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07404ab51f404f9411f79bd4f1fde654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1f2cb14589a2eb67788f0cbc7e4da98.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d005409790b3192705a181b2c8e7dfed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7b8d543c7d503fc1073503fc1d52faa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a69f434cc713ab1fe3286e2090f057f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/908b477b05cbf743e827c0fa20ec27ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
您最近一年使用:0次
8 . 已知等差数列
的公差不为零,
,且
成等比数列.
(1)求
的通项公式
(2)求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6be3f864d60fc147b6905979403f3b2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/719663ba0bd96380b9f34a0f72587fdb.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1c10e3915e2be8998267ace435cb6a2.png)
您最近一年使用:0次
2021-09-06更新
|
368次组卷
|
3卷引用:内蒙古赤峰市2020-2021学年高一下学期期末数学(文)试题(B )
名校
解题方法
9 . 已知数列
是公差为2的等差数列,
成等比数列.
(1)求
的通项公式;
(2)令
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6143ff1743d17cc9c92f44dbcca18359.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd27976ddb55760b42c26798e69c92b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/226c92888048cdd6817b308b48f435f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
2021-08-24更新
|
274次组卷
|
3卷引用:内蒙古通辽市重点校2022-2023学年高二上学期期末检测理科数学试题
10 . 设等差数列
的前n项和为Sn,其中
.
(1)求数列
的通项公式;
(2)若Sn,2
(an+1+1),Sn+2成等比数列,求正整数n的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/894aaec56149f880c7cf2bbc0f358d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78c945b5d808517d5945dffaa13633c4.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/894aaec56149f880c7cf2bbc0f358d2b.png)
(2)若Sn,2
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
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