Data Science Academy · 课时

均值、中位数和众数

寻找中心位置的三种方法

均值、中位数和众数 是 CoddyKit 上的免费 Data Science Academy 课时。这是第 1 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 Data Science Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Data Science Academy 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

Finding the Center

Before you analyze anything, you ask where the data sits. A measure of center answers that with one number that stands in for the whole column. 🎯

Mean: The Average

The mean adds up every value and divides by how many there are. It is the balance point of your data, the classic average you already know.

Mean in pandas

In pandas you never loop to average. One method call on a column gives you the mean instantly.

df["age"].mean()

When the Mean Misleads

One huge value can drag the mean far from where most points sit. The mean is sensitive to outliers, so it is not always the honest center.

Median: The Middle Value

The median is the value sitting exactly in the middle once you sort the data. Half the points fall below it and half fall above.

Median Resists Outliers

Because it only cares about position, the median barely moves when a wild value appears. For skewed data like income, it often tells a fairer story.

df["income"].median()

Mode: The Most Common

The mode is simply the value that shows up most often. It is the only center that also works for text categories, not just numbers.

df["color"].mode()

More Than One Mode

Data can tie for most frequent, giving you two or more peaks. That is why mode in pandas returns a Series, never a single guaranteed number.

Mean vs Median Gap

When mean and median drift far apart, your data is skewed. A big gap is your first hint that one tail is stretching the average.

Picking the Right Center

Use the mean for tidy symmetric data, the median when outliers lurk, and the mode for categories. The shape of your data decides for you.

One Call, Many Stats

You rarely compute these alone. The describe method hands you mean and more for every numeric column in a single line.

df.describe()

Quick Check

A salary column has a few extremely high earners pulling the average up.

Recap: Three Centers

You now know three ways to find the center: mean for the average, median for the middle, and mode for the most common. Match the tool to your data's shape. 👏

常见问题解答

「均值、中位数和众数」课时是免费的吗？

是的 — 「均值、中位数和众数」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Data Science Academy 课程的其余内容，请升级到 CoddyKit PRO。 Data Science Academy 课程共包含 4 节课。

「均值、中位数和众数」这节课中我会学到什么？

寻找中心位置的三种方法你通过在浏览器中直接运行的动手代码来练习 Data Science Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 Data Science Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 Data Science Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 1 节课，共 4 节。

「均值、中位数和众数」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 Data Science Academy 课中编写并运行代码吗？

能。每节 Data Science Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

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