Mean vs Median
Mean vs median compared — how each is calculated, how outliers affect them, and when to use which, with a free statistics calculator.
The mean is the average (sum ÷ count); the median is the middle value. They agree for symmetric data but diverge when the data is skewed or has outliers.
Mean vs Median at a glance
| Mean | Median | |
|---|---|---|
| Calculation | Sum ÷ count | Middle value (sorted) |
| Outliers | Strongly affected | Robust |
| Best for | Symmetric data | Skewed data, incomes |
When to use Mean
Use the mean for roughly symmetric data without big outliers.
When to use Median
Use the median for skewed data or when outliers would distort the average (e.g. income, house prices).
Tools for Mean & Median
Mean vs Median
如何计算基本概率？
用有利结果数除以所有等可能结果的总数即可。
“独立事件”是什么意思？
指一个事件的结果不会影响另一个事件。此时 P(A 且 B) = P(A)·P(B)，P(A 或 B) = P(A) + P(B) − P(A)·P(B)。
什么是二项分布？
指在 n 次独立试验中（每次成功概率均为 p），恰好出现 k 次成功的概率：P(X = k) = C(n, k) pᵏ (1−p)ⁿ⁻ᵏ。
赔率（Odds）和概率有什么区别？
概率 = 有利结果数 ÷ 总结果数；赔率 = 有利结果数 : 不利结果数。例如概率为 1/4 时，对应的赔率为 1 : 3。