NO.PZ2015120604000123
问题如下:
Which of the following is most likely to be true for t-distribution?
选项:
A.
As the sample size gets larger, the t-distribution approaches the normal distribution.
B.
The degrees of freedom is equal to n.
C.
The distribution is symmetry but more peaked than a standard normal distribution.
解释:
A is correct.
B is incorrect because the degrees of freedom is equal to n-1.
C is incorrect because t-distribution is less at the peak than a standard normal distribution.
在t分布中,自由度为:n-1;并且t分布的图相比正态分布要扁一些,所以B&C选项描述错误;而选项A为正确描述。
不是只有df变化,才会影响她的形态吗,更接近正态分布吗