Calculadora de Probabilidad de Unión Gratis
Calcula P(A o B) usando la regla de adición. Considera si los eventos son mutuamente excluyentes o no.
P(A or B)
0.700000
P(A or B) vs P(A)
Fórmula
## How to Calculate Union Probability ### Formula **P(A or B) = P(A) + P(B) - P(A and B)** The addition rule accounts for the overlap between events A and B. If you simply add P(A) and P(B), the intersection is counted twice, so you subtract P(A and B) once. For mutually exclusive events, P(A and B) = 0.
Ejemplo Resuelto
P(A) = 0.3, P(B) = 0.5, P(A and B) = 0.1. Find P(A or B).
- 01P(A or B) = P(A) + P(B) - P(A and B)
- 02P(A or B) = 0.3 + 0.5 - 0.1
- 03P(A or B) = 0.7
- 04P(Neither) = 1 - 0.7 = 0.3
Preguntas Frecuentes
What if the events are mutually exclusive?
If A and B cannot occur together, P(A and B) = 0, so P(A or B) = P(A) + P(B). This is the special addition rule.
Can P(A or B) exceed 1?
No. If your calculation gives a value above 1, check that P(A and B) is not too small or that P(A) and P(B) are valid. The intersection must satisfy P(A and B) <= min(P(A), P(B)).
How does this extend to three events?
P(A or B or C) = P(A) + P(B) + P(C) - P(A and B) - P(A and C) - P(B and C) + P(A and B and C). This is the inclusion-exclusion principle.
Aprender