老师，第2步的标准化中，分子减均值时为什么要用总体的均值10%？

NO.PZ2015120604000178

问题如下：

BIM is a well-developed public company and its market capitalization growth rates over past few decades are normally distributed.The population has a mean of 10% and a standard deviation of 5.4%. An investor wants to figure out the probability that BIM's average capitalization growth rate will over 12.32% in the next three years (all the data are monthly statistics).Which of the following option is most accurate?

选项：

0.5%.

1%.

5%.

解释：

A is correct.

It is appropriate to use the central limit theroy to calculate. Standard error=5.4%/ $\sqrt {\rm{36}}$ P(X＞12.32%)=P(Z＞ (12.32%-10%)/0.009)=P(Z＞2.58). So the corresponding probability is 0.5%.

是因为sample均值的期待E（x）=趋近于总体均值这个原理吗？但这里并没有说样本的均值是正态分布的，只说了population是正态分布的，怎么得出这一结论呢？

添加评论

1 个答案

已采纳答案

袁园_品职助教 · 2022年06月08日

嗨，从没放弃的小努力你好：

通过题干可以看出，这道题满足中心极限定理的条件 1. 总体方差已知是finite variance 2. N＞30 （因为是月度数据取值，所以sample size N=3*12=36）。所以可以得到X bar服从正态分布，且X bar的均值就为总体均值10%，X bar的标准差 (标准误) 即为已知的总体标准差除以根号N，也就是答案解析中的0.009。

注意中心极限定理是推导出均值是正态分布，而且也不要求总体的分布形态。

----------------------------------------------
就算太阳没有迎着我们而来，我们正在朝着它而去，加油！

添加评论

1
回答
0
关注
378
浏览

我要回答关注问题

相关问题

NO.PZ2015120604000178 问题如下 BIM is a well-velopepublic company anits market capitalization growth rates over past few cas are normally stributeThe population ha meof 10% ana stanrviation of 5.4%. investor wants to figure out the probability thBIM's average capitalization growth rate will over 12.32% in the next three years (all the ta are monthly statistics).Whiof the following option is most accurate? A.0.5%. B.1%. C.5%. A is correct. It is appropriate to use the centrlimit theroy to calculate.Stanrerror=5.4%/36\sqrt {\rm{36}}36P(X＞12.32%)=P(Z＞ (12.32%-10%)/0.009)=P(Z＞2.58). So the corresponng probability is 0.5%. 本题是求增长率大于12.3%的概率，为什么会用标准误来表示概率？

2024-01-10 13:53 1 · 回答

NO.PZ2015120604000178问题如下BIM is a well-velopepublic company anits market capitalization growth rates over past few cas are normally stributeThe population ha meof 10% ana stanrviation of 5.4%. investor wants to figure out the probability thBIM's average capitalization growth rate will over 12.32% in the next three years (all the ta are monthly statistics).Whiof the following option is most accurate?A.0.5%.B.1%.C.5%. A is correct. It is appropriate to use the centrlimit theroy to calculate.Stanrerror=5.4%/36\sqrt {\rm{36}}36P(X＞12.32%)=P(Z＞ (12.32%-10%)/0.009)=P(Z＞2.58). So the corresponng probability is 0.5%. 看不懂这道题的提干意思以及求解的顺序和逻辑，请老师解答的详细一些，谢谢

2024-01-03 19:21 1 · 回答

NO.PZ2015120604000178问题如下BIM is a well-velopepublic company anits market capitalization growth rates over past few cas are normally stributeThe population ha meof 10% ana stanrviation of 5.4%. investor wants to figure out the probability thBIM's average capitalization growth rate will over 12.32% in the next three years (all the ta are monthly statistics).Whiof the following option is most accurate?A.0.5%.B.1%.C.5%. A is correct. It is appropriate to use the centrlimit theroy to calculate.Stanrerror=5.4%/36\sqrt {\rm{36}}36P(X＞12.32%)=P(Z＞ (12.32%-10%)/0.009)=P(Z＞2.58). So the corresponng probability is 0.5%. 这道题为什么不考虑大于，按照单尾 1% 选择

2023-12-10 16:05 2 · 回答

NO.PZ2015120604000178 问题如下 BIM is a well-velopepublic company anits market capitalization growth rates over past few cas are normally stributeThe population ha meof 10% ana stanrviation of 5.4%. investor wants to figure out the probability thBIM's average capitalization growth rate will over 12.32% in the next three years (all the ta are monthly statistics).Whiof the following option is most accurate? A.0.5%. B.1%. C.5%. A is correct. It is appropriate to use the centrlimit theroy to calculate.Stanrerror=5.4%/36\sqrt {\rm{36}}36P(X＞12.32%)=P(Z＞ (12.32%-10%)/0.009)=P(Z＞2.58). So the corresponng probability is 0.5%. 为什么用标准误来计算呢，标准误在题干场景里是什么具体含义

2023-11-05 14:07 1 · 回答

NO.PZ2015120604000178问题如下BIM is a well-velopepublic company anits market capitalization growth rates over past few cas are normally stributeThe population ha meof 10% ana stanrviation of 5.4%. investor wants to figure out the probability thBIM's average capitalization growth rate will over 12.32% in the next three years (all the ta are monthly statistics).Whiof the following option is most accurate?A.0.5%.B.1%.C.5%. A is correct. It is appropriate to use the centrlimit theroy to calculate.Stanrerror=5.4%/36\sqrt {\rm{36}}36P(X＞12.32%)=P(Z＞ (12.32%-10%)/0.009)=P(Z＞2.58). So the corresponng probability is 0.5%. 请问到哪里找这个查表

2023-09-24 10:45 1 · 回答

老师，第2步的标准化中，分子减均值时为什么要用总体的均值10%？

1 个答案

1

0

378

相关问题