NO.PZ2017092702000138
问题如下:
For a small sample with unknown variance, which of the following tests of a hypothesis concerning the population mean is most appropriate?
选项:
A.
A t-test if the population is normally distributed
B.
A t-test if the population is non-normally distributed
C.
A z-test regardless of the normality of the population distribution
解释:
A is correct.
A t-test is used if the sample is small and drawn from a normally or approximately normally distributed population.
方差已知用Z,方差未知用t,非正态总体且小样本不可估计
正态分布与Z分布和T分布都关系是什么呢?Z分布是正态分布的简称吗?T分布一定会正态分布吗?