Conditional Probability Calculator — 公式
## How to Calculate Conditional Probability
### Formula
**P(A|B) = P(A and B) / P(B)**
Conditional probability measures how the probability of event A changes when we know event B has occurred. The vertical bar "|" is read as "given". P(B) must be greater than zero.
### Formula
**P(A|B) = P(A and B) / P(B)**
Conditional probability measures how the probability of event A changes when we know event B has occurred. The vertical bar "|" is read as "given". P(B) must be greater than zero.
计算示例
P(A and B) = 0.12 and P(B) = 0.4. Find P(A|B).
- P(A|B) = P(A and B) / P(B)
- P(A|B) = 0.12 / 0.4
- P(A|B) = 0.3
- As a percentage: 30%