问题如下:
An analyst is examining the monthly returns for two funds over one year. Both funds’ returns are non-normally distributed. To test whether the mean return of one fund is greater than the mean return of the other fund, the analyst can use:
选项:
A.a parametric test only.
B.a nonparametric test only.
C.both parametric and nonparametric tests.
解释:
B is correct.
There are only 12 (monthly) observations over the one year of the sample and thus the samples are small. Additionally, the funds’ returns are non-normally distributed. Therefore, the samples do not meet the distributional assumptions for a parametric test. The Mann–Whitney U test (a nonparametric test) could be used to test the differences between population means
是不是所有学过的参数检验的前提就是一定要符合正态分布?不符合的就是非参数检验,这样理解对吗?