NO.PZ2017092702000107
问题如下:
A population has a non-normal distribution with mean µ and variance σ2. The sampling distribution of the sample mean computed from samples of large size from that population will have:
选项:
A.the same distribution as the population distribution.
B.its mean approximately equal to the population mean.
C.its variance approximately equal to the population variance.
解释:
B is correct.
Given a population described by any probability distribution (normal or nonnormal) with finite variance, the central limit theorem states that the sampling distribution of the sample mean will be approximately normal, with the mean approximately equal to the population mean, when the sample size is large.
给定具有有限方差的任何概率分布(正态或非正态)描述的总体,中心极限定理指出,当样本大小足够大的时候,样本均值为正态分布,其中样本均值等于总体均值。
RT