重学 Statistics, Cha11 Inferences About Population Variances

11.1 Inferences About a Population Variance

对于 chi-square distribution, 百度百科是这样写的：

Interval Estimation

We will use the notation X2α to denote the value for the chi-square distribution that provides an area or probability of α to the right of the X2α value.





那就是


经过变换，可以得到：

Hypothesis Testing

用得到的值，去表里找到 p-value。进行比对，和之前做 hypothesis test的方法一样，就可以知道是 reject or do not reject.

11.2 Inferences About Two Population variances