问题如下图:
选项:
A.
B.
C.
老师,方差未知和小样本不是不能估计吗? 解释:
NO.PZ2017092702000138问题如下For a small sample with unknown variance, whiof the following tests of a hypothesis concerning the population meis most appropriate?A.A t-test if the population is normally stributeB.A t-test if the population is non-normally stributeC.A z-test regaress of the normality of the population stribution A is correct. A t-test is useif the sample is small anawn from a normally or approximately normally stributepopulation.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 老师 虽然做对了,但是C麻烦翻译下,谢谢
NO.PZ2017092702000138问题如下For a small sample with unknown variance, whiof the following tests of a hypothesis concerning the population meis most appropriate?A.A t-test if the population is normally stributeB.A t-test if the population is non-normally stributeC.A z-test regaress of the normality of the population stribution A is correct. A t-test is useif the sample is small anawn from a normally or approximately normally stributepopulation.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?