问一道题：NO.PZ2015120604000178 [ CFA I ]

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.

$Standatd error = \frac{5.4 %/}{\sqrt{6}} = 0.009$

P(X＞12.32%)=P(Z＞ (12.32%-10%)/0.009)=P(Z＞2.58). So the corresponding probability is 0.5%.

这题看完题目没有思路，不知道从哪里着手。请老师讲解一下？

添加评论

1 个答案

已采纳答案

星星_品职助教 · 2020年04月20日

同学你好，

这道题要求是BIM的 average capitalization growth rate超过12.32%的概率，这里的关键词是“average”，说明要求的是是 X bar也就是X的均值＞12.32%的概率。所以就要看X bar是什么分布（如果是正态分布，就可以做标准化）。然后通过题干可以看出，这道题满足中心极限定理的条件 1. 总体方差已知 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。接下来就是正常的正态分布标准化计算了，可以得到X bar＞12.32%标准化后相当于Z＞2.58，查表或者用背的2.58对应99%置信区间的规律都可以得出概率为0.5%，

添加评论

H. · 2020年04月21日

谢谢老师，突破点突然就清楚了。

星星_品职助教 · 2020年04月21日

加油～

1
回答
0
关注
375
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

问一道题：NO.PZ2015120604000178 [ CFA I ]

1 个答案

1

0

375

相关问题