NO.PZ2018062001000012
问题如下：
Assume there is an increase in degree of freedom, t-distribution will have:
选项：
A. fatter tails and be more peaked.
B. fatter tails and be less peaked.
C. thinner tails and be more peaked.
解释：
C is correct.
The t-distribution will have thinner tails and be more peaked if the degree of freedom is increasing. When degree of freedow is close to infinite, the distribution tends to be normal distributed.
请问自由度是阿尔法吗？增加的话，置信区间不就小了么…小的话t分布不就越不正态分布？