月份 | 2017.12 | 2018.01 | 2018.02 | 2018.03 | 2018.04 |
月份编号 | 1 | 2 | 3 | 4 | 5 |
销量(万量) | 0.5 | 0.6 | 1 | 1.4 | 1.7 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3f9a08ee8bc2746ce20df23b40fdb46.png)
(2)2018年6月12日,中央财政和地方财政将根据新能源汽车的最大续航里程(新能源汽车的最大续航里程是指理论上新能源汽车所装的燃料或电池所能够提供给车跑的最远里程)对购车补贴进行新一轮调整.已知某地拟购买新能源汽车的消费群体十分庞大,某调研机构对其中的200名消费者的购车补贴金额的心理预期值进行了一个抽样调查,得到如下一份频数表:
补贴金额预期值区间(万元) | ||||||
频数 | 20 | 60 | 60 | 30 | 20 | 10 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/671f43c79d612c93a6d160335e86e177.png)
(ii)将频率视为概率,现用随机抽样方法从该地区拟购买新能源汽车的所有消费者中随机抽取3人,记被抽取的3人中对补贴金额的心理预期值不低于3万元的人数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b734e8f1546481e3eb4976008a045de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefcbf930fe7ffbfeaba7f13cdba3884.png)
附:①回归直线的斜率和截距的最小二乘估计公式分别为:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18cb55306c88cb561e0bf5b300a18ac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fa16fa102e7d1186183a93447575199.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b99b84c4fe266d5fb3457231c3f3279.png)
2 . 某超市计划按月订购一种酸奶,每天进货量相同,进货成本每瓶4元,售价每瓶6元,未售出的酸奶降价处理,以每瓶2元的价格当天全部处理完.根据往年销售经验,每天需求量与当天最高气温(单位:℃)有关.如果最高气温不低于25,需求量为500瓶;如果最高气温位于区间[20,25),需求量为300瓶;如果最高气温低于20,需求量为200瓶.为了确定六月份的订购计划,统计了前三年六月份各天的最高气温数据,得下面的频数分布表:
最高气温 | [10,15) | [15,20) | [20,25) | [25,30) | [30,35) | [35,40) |
天数 | 2 | 16 | 36 | 25 | 7 | 4 |
以最高气温位于各区间的频率估计最高气温位于该区间的概率.
(1)求六月份这种酸奶一天的需求量不超过300瓶的概率;
(2)设六月份一天销售这种酸奶的利润为Y(单位:元),当六月份这种酸奶一天的进货量为450瓶时,写出Y的所有可能值,并估计Y大于零的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b1d460a905b050f32eb6f8790b281a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71bc817b4e035b4f89640d18f5a76a9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b4f8e11b4a5e9ec1ea5426ddd336377.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/447e4fddd308d0bdb62f5018d96e9515.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e6772bcade4051926e56ec947c0cf4.png)
![](https://img.xkw.com/dksih/QBM/2018/7/15/1989101539557376/1990296196898817/STEM/3ab1579e2c8f4d5888769c3749ffced5.png?resizew=202)
A.2至3月份的收入的变化率与11至12月份的收入的变化率相同 |
B.支出最高值与支出最低值的比是6:1 |
C.第三季度的月平均收入为50万元 |
D.利润最高的月份是2月份(利润=收入-支出) |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
2 | 3 | 4 | 5 | 6 | 8 | 9 | 11 | |
1 | 2 | 3 | 3 | 4 | 5 | 6 | 8 |
(Ⅰ)请用相关系数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/130b1209318cc9a9ea61080b85dd6841.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70e44add7ea8847e500b9ae8929ad46b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82408d6ec5d06930a8da111d8726c628.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70e44add7ea8847e500b9ae8929ad46b.png)
(Ⅱ)根据1的判断结果,建立
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70e44add7ea8847e500b9ae8929ad46b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92ca51c7b84b6d46cad7f0e594aae7a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3617671ab9daae844ca0a46066fe7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6181adbd59883be9152063bd45176f73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a87796ee30e6c5d5e6b6285b32abe10c.png)
附参考公式:回归方程中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db6103cb0f1d2bd6b19235d53ee7e98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abc5505526d11946ca7d3a4421a9e08f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0032ca31e3cba58f973c6e75b907fb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32944016c1dc9bc9c7191750f7e59c65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a58291bd91befe1061530246da983727.png)
相关系数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8183b9b85fe518cbe4edc4798861a1aa.png)
参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b0ac8100d25e8f996672fee4a5159ba.png)