Geometric Verteilung RechnerFormel

## How to Calculate Geometric Distribution Probability

### Formula

**P(X = k) = (1-p)^(k-1) * p**

The geometric distribution models the number of trials needed to get the first success. Each trial is independent with success probability p. The probability of needing exactly k trials means k-1 failures followed by 1 success. The expected number of trials is 1/p.

Lösungsbeispiel

A basketball player has a 20% free-throw rate. What is the probability the first basket is made on the 5th attempt?

  1. P(X=5) = (1-0.2)^(5-1) * 0.2
  2. = 0.8^4 * 0.2
  3. = 0.4096 * 0.2
  4. = 0.08192
  5. Expected trials until first success = 1/0.2 = 5