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    Binomial Probability Calculator

    Calculate binomial probabilities and distribution statistics

    Quick examples:
    Quick examples:

    Distribution Visualization

    Probability

    24.6094%
    P(X = 5) = 0.24609375
    P(X < 5): 37.6953%
    P(X ≤ 5): 62.3047%
    P(X > 5): 37.6953%
    P(X ≥ 5): 62.3047%

    Distribution Statistics

    5.0000
    Mean (μ)
    2.5000
    Variance (σ²)
    1.5811
    Std Dev (σ)

    Full Distribution

    kP(X=k)%
    00.0009770.10%
    10.0097660.98%
    20.0439454.39%
    30.11718811.72%
    40.20507820.51%
    50.24609424.61%
    60.20507820.51%
    70.11718811.72%
    80.0439454.39%
    90.0097660.98%
    100.0009770.10%

    Binomial Distribution

    P(X=k) = C(n,k) × p^k × (1-p)^(n-k)
    μ = np, σ² = np(1-p)

    About Binomial Distribution

    The binomial distribution models the number of successes in a fixed number of independent trials, each with the same probability of success.

    When to Use Binomial Distribution

    • Fixed number of trials (n)
    • Each trial has only two outcomes (success/failure)
    • Trials are independent
    • Probability of success (p) is constant

    Common Examples

    • Coin flips: Getting heads in 10 tosses
    • Quality control: Defective items in a batch
    • Medical trials: Success rate of a treatment

    Parameters

    • n: Number of independent trials
    • k: Number of successes we're calculating probability for
    • p: Probability of success on each trial (between 0 and 1)