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:
A.0.5%.
B.1%.
C.5%.
解释:
A is correct.
It is appropriate to use the central limit theroy to calculate. Standard error=5.4%/ P(X>12.32%)=P(Z> (12.32%-10%)/0.009)=P(Z>2.58). So the corresponding probability is 0.5%.
谢谢老师解答!
本题计算出的z-statistic就约为2.58,单尾0.5%的显著性水平对应的关键值也为2.58,检测值就相当于是落在了关键值上。原题问的是大于的情况,在0.5%的显著性水平下,不就属于not to reject H0的情况吗?如果选B,是不是更合理一些?