12.5:章节公式回顾
- Page ID
- 204468
12.1 两个方差的检验
\[H_{0} : \frac{\sigma_{1}^{2}}{\sigma_{2}^{2}}=\delta_{0}\nonumber\]
\[H_{a} : \frac{\sigma_{1}^{2}}{\sigma_{2}^{2}} \neq \delta_{0}\nonumber\]
如果\(\delta_{0}=1\)那么
\[H_{0} : \sigma_{1}^{2}=\sigma_{2}^{2}\nonumber\]
\[H_{a} : \sigma_{1}^{2} \neq \sigma_{2}\nonumber\]
测试统计数据为:
\[F_{c}=\frac{S_{1}^{2}}{S_{2}^{2}}\nonumber\]
12.3 F 分布和 F 比率
\(S S_{\mathrm{between}}=\sum\left[\frac{\left(s_{j}\right)^{2}}{n_{j}}\right]-\frac{\left(\sum s_{j}\right)^{2}}{n}\)
\(S S_{\mathrm{total}}=\sum x^{2}-\frac{\left(\sum x\right)^{2}}{n}\)
\(S S_{\text {within}}=S S_{\text {total}}-S S_{\text {between}}\)
\(d f_{\mathrm{between}}=d f(n u m)=k-1\)
\(d f_{\text {within}}=d f(\text {denom})=n-k\)
\(M S_{\text {between}}=\frac{S S_{\text {between}}}{d f_{\text {between}}}\)
\(M S_{\text {within}}=\frac{S S_{\text {within}}}{d f_{\text {within}}}\)
\(F=\frac{M S_{\text {between}}}{M S_{\text {within}}}\)
- \(k\)= 组数
- \(n_j\)= 第 j 组的大小
- \(s_j\)= 第 j 组中值的总和
- \(n\)= 所有值(观测值)的总数
- \(x\)= 来自数据的一个值(一个观测值)
- \(s_{\overline{x}}^{2}\)= 样本均值的方差
- \(s^2_{pooled}\)= 样本方差的平均值(合并方差)