NO.PZ2022123001000088
问题如下:
There are three fat-tailed samples.The followings are their standard error of the sample mean and sample variance. Which sampling distribution of the sample mean has fatter tails?
选项:
解释:
With the knowing standard deviation and standard error, the sample size(n) is:
nA=4; nB=16; nC=9
According to the central limit theorem, a sampling distribution of the sample mean will be approximately normal only if the sample size n is large. As n increase, the sampling distribution of the the sample mean will has less fat tails. So A with a smallest size is correct.
这道题的解析不是很明白,n越大越接近正态分布可以理解,但是偏离正态分布也有可能是platylkurtic,那相较于normal distribution就是thin-tailed,为什么这边就默认样本量越小就只是leptokurtic(fat-tailed)的情况,是不是还有其他条件没考虑到?还请老师再解答一下。谢谢