The 2 sigma comes from two standard deviation, sigma, the symbol for standard deviation.

2 sigma 来自两个均方差，sigma 均方差的符号。

But of 24 GIDS patients who had been prescribed puberty blockers, a third had BMD scores in the bottom 2% of their age groups (more that two standard deviations below the mean).

但在24名服用了青春阻滞药的GIDS患者中，有三分之一的骨密度评分在其年龄组的最后2%(比平均值低两个标准差以上)。

It is the standard deviation of price fluctuations expected over a set timeline (30 days for the MOVE and the VIX), assuming they are distributed along a bell curve and that options are priced accordingly.

在给定时间线（MOVE指数和VIX指数均为30天）内预价格波动的标准偏差，假设的价格波动沿着钟形曲线分布，并且权据此定价的。

So based on the data given for this population, and using the standard deviation formula, what do you think this variable is?

以这个人口数据为基础再用标准差，觉得变量多少？

Readers have to wait until page 65 before reaching the first serious concept, standard deviation, which feels too late.

读者得等上65页才能接触到第一个严肃的统计学概念——标准差，让人感觉进度太慢。

And I woke up in a head injury rehab ward, and I had been withdrawn from college, and I learned that my IQ had dropped by two standard deviations, which was very traumatic.

我在休息室醒来以后发现头部重伤，我从大学里休学，别人告知我智商下降了2个标准差，情况非常非常糟糕。

If you personalize, then you get two standard deviations, more effective learning.

如果进行个性化学习，那么学习效果会提升两个标准差。

That's 2.1 effect size, two standard deviations away from the norm.

那2.1的效果量，比常态高出两个标准差。

And the VIX were close to three standard deviations above the long-term median.

而VIX指数接近长中位数上方的三个标准差。

I'm not that far out of two standard deviations down on Apple.

我在苹果司的表现没有差到两个标准差那么远。

They are a couple standard deviation outliers.

他们几个标准差的异常值。

None of these results, it must be said, yet quite reaches the gold standard of confirmation, known as 5-sigma (ie, five standard deviations from the mean) which particle physicists normally demand before they will call something a " discovery" .

必须说， 这些结果中没有一个完全达到确认的黄金标准，称为 5- sigma（ 即， 与平均值相差五个标准差） ，粒子物理学家在将某事称为“ 发现” 之前通常要求这一标准。

So, in short, we have two parameters; one  describing the mean, one describing the standard deviation and they're all tied together  in this big formula involving an e and a pi.

所以，简而言之，我们有两个参数；一个描述均值， 一个描述标准差， 它们都与这个包含e和π的大联系在一起。

So knowing the from the mean and the standard deviation and the normal curve calculations we can calculate how often he'll win in three moves, okay?

所以， 知道了平均值、标准差和正态曲线的计算方法， 我们可以计算出他会在三步内获胜的频率，好吗？

This is actually going to be a normal distribution regardless of-- this one just has a well-defined standard deviation mean.

这实际上将一个正态分布，无论——这个只有一个明确定义的标准差平均值。

Both on the left and right hip, you're about one and a half to 1.7 standard deviations below the mean.

左右髋部的情况也不太理想，均比平均值低了约1.5到1.7个标准差。

The critical variable was the standard deviation of the means divided by the mean of the standard deviations.

关键变量均值的标准差除以标准差均值所得的比值。

Raymond, you were the one who scored one standard deviation higher than Debra.

雷蒙德，的成绩应该比黛布拉高一个等级。

Do you know how to calculate the standard deviation ?

知道如何计算标准差吗？

What if we got two standard deviations more conscientious?

如果我们得到两个更认真的标准差呢？