单选题

If the distribution of the population from which the samples are drawn is positively skewed, and given that the sample size is large, the sampling distribution of the sample means is most likely:

A、 approximately normally distributed.
B、 to have a variance equal to that of the entire population.
C、 to have a mean smaller than the mean of the entire population.

【正确答案】 A

【答案解析】

A is correct. The central limit theorem establishes that the sampling distribution of sample means will be approximately normal, will have a mean equal to the population mean, and will have a variance equal to the population variance divided by the sample size.