1 .
地区农科所统计历年冬小麦每亩产量的数据,得到频率分布直方图(如图1),考虑到受市场影响,预测该地区明年冬小麦统一收购价格情况如表1(该预测价格与亩产量互不影响).
![](https://img.xkw.com/dksih/QBM/2023/1/4/3145412199759872/3146384747102208/STEM/ae25768e4bba42b2ac343d6da3c72fc1.png?resizew=336)
假设图1中同组的每个数据用该组区间的中点值估算,并以频率估计概率.
(1)试估计
地区明年每亩冬小麦统一收购总价为
元的概率;
(2)设
地区明年每亩冬小麦统一收购总价为
元,求
的分布列和数学期望;
(3)
地区农科所研究发现,若每亩多投入
元的成本进行某项技术改良,则可使每亩冬小麦产量平均增加
.从广大种植户的平均收益角度分析,你是否建议农科所推广该项技术改良?并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/2023/1/4/3145412199759872/3146384747102208/STEM/ae25768e4bba42b2ac343d6da3c72fc1.png?resizew=336)
明年冬小麦统一收购价格(单位:元![]() | ![]() | ![]() |
概率 | ![]() | ![]() |
表1
假设图1中同组的每个数据用该组区间的中点值估算,并以频率估计概率.
(1)试估计
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d69c0fc5595aadf8e59662c20c515b58.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9740bae87cbcfb6d389145d64cfd42ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59f0e84413d0eb3bc124f95b7b371ce3.png)
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