Calcolatore di Probabilità
P(¬A): Complementare
0.6
P(A ∪ B)
0.58
P(A ∩ B)
0.12
P(A | B)
0.4
P(B | A)
0.3
Domande Frequenti
Calcolo probabilità
Cos'è il Teorema di Bayes?
P(A|B) = P(B|A)·P(A) / P(B). Permette di aggiornare la probabilità di A alla luce di nuove evidenze (B). Base del ragionamento probabilistico, statistica bayesiana e ML.
Eventi indipendenti o no?
Due eventi A e B sono indipendenti se P(A ∩ B) = P(A)·P(B), cioè il verificarsi di uno non influenza l'altro. Altrimenti sono dipendenti e serve fornire P(A ∩ B) esplicitamente.
What does the Bayes theorem say?
It says how to update the probability of a hypothesis when new information arrives: you multiply the starting probability by the probability of the observed data, and divide by the probability of that data.
When are two events independent?
When the probability that they both happen is the product of their probabilities, that is, when one happening does not change the other. When they are dependent, the joint probability goes in by hand.
What is the difference between union and intersection?
The union is the probability that at least one of the two events happens, the intersection that both do. In the union the probabilities are added and the intersection subtracted, so it is not counted twice.