xuruilong100 发表于 2014-6-2 15:39
对收益率数据做正态性检验
大神,我理解的是为什么收益率不能实现正态分布。我这么理解对吗?因为前面几题已经让我对收益率数据做正态性检验了,所以这题我不知道是总结文字还是继续让我用hypothesis testing。
对了 我还可以问一下,
在这句话中:“Under the assumption that the stock returns of each asset are drawn from an
independently and identically distributed normal distribution, are the expected
returns statistically dierent from zero for each asset? State clearly the null and
alternative hypothesis in each case.” 意思是让我把每个公司的收益率原假设=0, 备择假设不等于0,然后检验吗?
还有这句话:Assume the stock returns from each asset are independent from each other, are
the mean returns statistically dierent from each other? 这句话中的independent是独立的意思吗?
因为紧接着下一题是Is the assumption of independence realistic? If not, re-test the hypotheses in
Question 5 using appropriate test statistics. 但是independent是独立的话,我该怎么假设呢?
求大神帮忙啊!!!晚上12点之前交论文。现在卡在这几题中。