Posted by haifeng on 2026-06-07 10:39:11 last update 2026-06-07 15:32:12 | Answers (0) | 收藏
\[ t=\frac{\bar{X}_1-\bar{X}_2}{\sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2}}} \]
校正 $t$ 检验的自由度计算公式:
\[ df = \dfrac{(\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2})^2 }{\frac{(s_1^2 / n_1)^2 }{n_1-1}+\frac{(s_2^2/n_2)^2}{n_2-1}} \]
