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A binomial distribution describes the probability of getting a specific number of “successes” in a fixed number of independent trials, where each trial has only two possible outcomes (success or failure) and the probability of success stays the same each time. The formula: The probability of getting exactly k successes in n trials is: P(X = k) = C(n,k) × p^k × (1-p)^(n-k) What it looks like: The distribution is often bell-shaped / normal distribution like (especially when n is large and p is near 0.5), but can be skewed if p is very small or very large. Key parameters: Mean (expected value) = n × p Variance = n × p × (1-p)