Probability Formula:
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The nth term probability calculates the chance of exactly k successes in n independent trials, each with success probability p. This is known as the binomial probability distribution.
The calculator uses the binomial probability formula:
Where:
Explanation: The formula accounts for all possible ways k successes can occur in n trials, weighted by the probability of each specific sequence.
Details: Binomial probability is fundamental in statistics, used in quality control, medical testing, risk assessment, and many other fields requiring probability analysis of independent events.
Tips: Enter number of trials (n ≥ 1), number of successes (0 ≤ k ≤ n), and probability (0 ≤ p ≤ 1). All values must be valid.
Q1: What's the difference between binomial and other distributions?
A: Binomial is for discrete yes/no outcomes with fixed trials and constant probability, unlike Poisson (for rare events) or Normal (continuous).
Q2: When is binomial probability appropriate?
A: When trials are independent, probability is constant, and there are only two possible outcomes per trial.
Q3: What if I need cumulative probability?
A: This calculates exact probability. For "k or more" or "k or less" you'd need to sum multiple probabilities.
Q4: Are there limitations to binomial probability?
A: It assumes independence between trials and constant probability. For dependent events, other models are needed.
Q5: How accurate is this calculator?
A: Very accurate for n up to about 1000. For very large n, normal approximation may be better.