Skip to content
START WITH A QUESTION

What would you like to understand?

Find an answer. See the moment it becomes clear. Follow the idea further.

← Concept directory

Answers for “何时联合概率等于各个概率的乘积?”

2 keyword matches

Understanding your question. You can explore the search results below now.

Know when to use it

↗

The joint probability P(A and B) is equal to the product of the individual probabilities P(A)P(B)P(A)P(B) if and only if the events A and B are independent. Independence means that the occurrence of one event does not affect the probability of the other, which is mathematically expressed as P(B|A) = P(B)P(B) (assuming P(A)>0P(A) > 0).

Conditions: Events A and B are independent.; For the conditional equality P(B|A) = P(B)P(B), event A must have positive probability.

Understand why

↗

The formula P(A and B) = P(A)P(B)P(A)P(B) is crossed out because it is only valid for independent events. The video emphasizes the general multiplication rule, P(A and B) = P(A)PP(A)P(B|A), which works for both independent and dependent events.

Conditions: The events A and B may be dependent.; The general multiplication rule P(A and B) = P(A)PP(A)P(B|A) applies regardless of independence (assuming P(A)>0P(A) > 0).