NO.PZ2015120604000112
问题如下：
Which of the following formula is correct to calculate the standard error of the sample mean with large sample size n and finitevariance σ2?
选项：
A. Sx¯=sample standard deviation × squared root of n
B. Sx¯=sample standard deviation × n
C. Sx¯=sample standard deviation / squared root of n
解释：
Sx¯=S / squared root of n is the formula that used to calculate the standard error considering large n and unknown populatioin standard deviation.
Sx¯=S / squared root of n 这个公式是用于计算标准误：当n本身很大并且总体的标准差未知。
C我理解，但是A与C一样啊
