问题如下:
A population has a known mean of 1,000. Suppose 1,600 samples are randomly drawn (with replacement) from this population. The mean of the observed samples is 998.7, and the standard deviation of the observed samples is 100. What is the standard error of the sample mean?
选项:
A.0.025
B.0.25
C.2.5
D.25
解释:
This is , or = = 2.5. Other numbers are irrelevant.
麻烦老师辨析两个概念standard error of sample mean和standard deviation of observed sample.
standard error sample mean指的是不是抽取n次sample,每一次的sample mean的方差?