云烟2023 · 2020年12月23日
问题如下：
If the mean P/E of 30 stocks in a certain industrial sector is 18 and the sample standard deviation is 3.5, standard error of the mean is CLOSEST to:
选项：
A. 0.12
B. 0.34
C. 0.64
D. 1.56
解释：
C is correct.
考点 ： The Central Limit Theorem
解析 ： The standard error of the sample mean is the standard deviation of the distribution of the sample means. And it is calculated as:
So, standard error of the mean = = = 0.64
n是30吗？为什么不是18？P/E是什么意思？
NO.PZ2018122801000033 问题如下 If the meP/E of 30 stocks in a certain instrisector is 18 anthe sample stanrviation is 3.5, stanrerror of the meis CLOSEST to: 0.12 0.34 0.64 1.56 C is correct.考点 The CentrLimit Theorem解析 The stanrerror of the sample meis the stanrviation of the stribution of the sample means. Anit is calculateas:So, stanrerror of the me= s/ns/\sqrt ns/n = 3.5/303.5/\sqrt{30}3.5/30 = 0.64 老师好，还是有点混乱，分不清。想请问下如果这一句 “sample stanrviation is 3.5”，改成“sample mestanrviation is 3.5”的话，本题答案/标准误是不是直接就是3.5？
老师你好，请问这个答案怎么算出来的？我把数字带进去是3.5/根号下30=0.44，算不出答案里的数字，请问我哪里算出错了吗
