===== 方差未知情况下总体均值的估计（Estimation of Population Mean with Unknown Variance） =====

  * 在这种情况下，总体的方差σ未知，我们可以用样本均值的标准误来估计总体方差。
  * In this situation, where the population variance σ is unknown, we can estimate the population variance using the standard error of the sample mean.

  * 这时我们采用t检验，误差区间的大小为相应置信水平下的t<sub>crit</sub>。
  * In this case, we use a t-test, with the margin of error being the corresponding t<sub>crit</sub> at the desired confidence level.

  * 利用t检验的公式
  * Using the formula for the t-test
{{ ::总体均值估计.jpg?nolink&150 |}}
可以得出总体均值μ的估计区间。
This allows us to obtain an estimation interval for the population mean μ.