Let's get the calculator out to actually figure out our sample variance.

让我们用计算器实际计算出我们的样本方差。

Now what is my sample variance?

现在我的样本方差是多少？

Now given this sample here, what is my sample mean and my sample variance?

现在给定这个样本，我的样本均值和样本方差是多少？

My sample standard deviation is just going to be the square root of my sample variance.

我的样本标准差只是样本方差的平方根。

Our sample variances for each of these distributions.

我们针对这些分布中的每一个的样本方差。

We can approximate these with our sample variances for each of these distributions.

我们可以用每个分布的样本方差来近似这些。

If you take your sample standard deviation, 4.67 and you square it, you get your sample variance.

如果您取样本标准差 4.67 并将其平方，则得到样本方差。

Plus my sample standard deviation for the control squared, which is the sample variance.

加上我的控制平方样本标准偏差，即样本方差。

Remember, this is a sample variance, and we want to get the best estimator of the real variance of this distribution.

请记住，这是一个样本方差，我们希望获得该分布真实方差的最佳估计值。

So your sample variance, when you do it this way, it might turn out a little bit low.

所以你的样本方差，当你这样做的时候，结果可能会有点低。

So then we would have gotten the sample variance at 9.70.

那么我们就会得到 9.70 的样本方差。

Now let's also figure out our sample variance because we can use it later for building our confidence interval.

现在让我们也算出我们的样本方差，因为我们以后可以用它来建立我们的置信区间。

Sample variance is going to be equal to the sum of my squared distances to the mean divided by my samples minus 1.

样本方差将等于我与均值的平方距离之和除以我的样本减 1​​。

So this is going to be our sample standard deviation one squared, which is the sample variance for that distribution, over 100.

所以这将是我们的样本标准偏差的平方，这是该分布的样本方差， 超过 100。

So our sample variance is-- well, I'll just say 0.246.

所以我们的样本方差是——好吧，我就说 0.246。

And actually this is what some people often refer to, when they talk about sample variance.

事实上，这就是一些人在谈论样本方差时经常提到的。

The variance of a sample, or sample variance, or unbiased sample variance-- and that's why we're going to divide by n minus 1.

样本的方差，或样本方差，或无偏样本方差——这就是我们要除以 n 减 1 的原因。

It is equal to-- it is our sample variance-- I'll write it over here-- our sample variance is equal to 0.246.

它等于——这是我们的样本方差——我会在这里写下来——我们的样本方差等于 0.246。

So we might just say, well, maybe a good way to take the sample variance is, do it the same way.

所以我们可能会说，好吧，也许获取样本方差的一个好方法是， 以同样的方式进行。

Our sample variance here-- so let me draw a sample variance-- we're going to take the weighted sum of the square differences from the mean and divide by this minus 1.

我们这里的样本方差——所以让我画一个样本方差——我们将取平均值的平方差的加权和除以这个负 1。