Wahrscheinlichkeits-Rechner

Berechnen Sie Wahrscheinlichkeiten für verschiedene Szenarien mit Schritt-für-Schritt-Lösungen

P(A and B) - Provide P(A ∩ B) or choose an assumption

Provide the joint probability or choose an assumption below.

Independent events: P(A|B) = P(A) - occurrence of B doesn't affect A. Example: Two separate coin flips.

Mutually exclusive events: P(A ∩ B) = 0 - events cannot occur together. Example: Rolling a 2 or a 5 on a single die.

⚠️ Events cannot be both independent and mutually exclusive (unless one has probability 0).

Ergebnisse

Geben Sie Werte ein und klicken Sie auf Berechnen, um das Ergebnis zu sehen.

Probability Calculations

Probability measures the likelihood of an event occurring, expressed as a number between 0 and 1 (or 0% and 100%). Key probability rules include:

  • AND (Intersection): P(A and B) = P(A) × P(B) for independent events
  • OR (Union): P(A or B) = P(A) + P(B) - P(A and B)
  • Conditional: P(A|B) = P(A and B) / P(B) - probability of A given B
  • Complement: P(A') = 1 - P(A) - probability of A not occurring
  • Independent Events: P(A|B) = P(A) - occurrence of B doesn't affect A
  • Mutually Exclusive: P(A and B) = 0 - events cannot occur together

Understanding these rules helps in calculating probabilities for complex scenarios involving multiple events, such as games of chance, risk assessment, and statistical inference.

\(P(A \cup B) = P(A) + P(B) - P(A \cap B), P(A|B) = \frac{P(A \cap B)}{P(B)}, P(A') = 1 - P(A)\)

Worked Examples

Example 1

\(\text{Rolling a die: } P(\text{even}) = \frac{3}{6} = 0.5 \text{ or } 50\%\)

Example 2

\(\text{Two coins: } P(\text{both heads}) = 0.5 \times 0.5 = 0.25 \text{ or } 25\%\)
Probability Calculator | MathCalcLab | MathCalcLab