单选题
From a population of 5000 observations, a sample of n=100 is selected.
Calculate the standard error of the sample mean if the population standard
deviation is 50.
A. 4.48.
B. 5.00.
C. 4.00.
【正确答案】
B
【答案解析】The standard error of the sample mean equals the standard deviation of the population divided by the square root of the sample size: 50/(100)1/2=5.