1 英语愿意

正态分布 Normal distribution

2 英文解释

2.1 Normal Distribution Noun [ C Or U ] MATHEMATICS Specialized

an arrangement of data in which most values are near the centre of the range and gradually become fewer towards each end, shown in a graph as the shape of a bell.

正态分布

例句：

• The resulting variable has a nearly normal distribution.
• Normal distributions consistently occur only when they involve random events and a large sample.
  正态分布只有在涉及随机事件和大样本时才会持续出现。

2.2 Normal Adjective

ordinary or usual; the same as would be expected

普通的；平常的；通常的

例句：

• a normal working day
  正常工作日
• Lively behaviour is normal for a four-year-old child.
  4岁的孩子好动是正常的。
• It’s normal for couples to argue now and then.
  夫妻之间偶尔发生口角是很平常的。
• They were selling the goods at half the normal cost.
  他们正半价销售那些商品。
• The temperature was above/below normal for the time of year.
  气温高于／低于往年同期的正常值。
• Things are back to normal now that we’ve paid off all our debts.
  我们偿还了所有债务，一切又恢复了正常。

2.3 What Is Normal Distribution?

Data can be “distributed” (spread out) in different ways.

But there are many cases where the data tends to be around a central value with no bias left or right, and it gets close to a “Normal Distribution” like this:

The blue curve is a Normal Distribution. The yellow histogram shows some data that follows it closely, but not perfectly (which is usual).

It is often called a “Bell Curve” because it looks like a bell.

3 中文解释

正态分布（Normal distribution），也称“常态分布”，又名高斯分布（Gaussian distribution），最早由棣莫弗（Abraham de Moivre）在求二项分布的渐近公式中得到。C.F.高斯在研究测量误差时从另一个角度导出了它。P.S.拉普拉斯和高斯研究了它的性质。是一个在数学、物理及工程等领域都非常重要的概率分布，在统计学的许多方面有着重大的影响力。

正态曲线呈钟型，两头低，中间高，左右对称因其曲线呈钟形，因此人们又经常称之为钟形曲线。

若随机变量X服从一个数学期望为μ、方差为σ²的正态分布，记为N(μ，σ²)。其概率密度函数为正态分布的期望值μ决定了其位置，其标准差σ决定了分布的幅度。当μ = 0,σ = 1时的正态分布是标准正态分布。

4 感想体会

Normal distribution，其实就是普通的、平常的、通常的意思，不知道为什么要翻译成正态，让人不知所以。

正态分布非常常见，比如身高，绝大多数人的身高在180cm左右，160cm以下、200cmm以上的都很少。