This page performs calculations based on counting laws, without requiring a dataset. We choose the law Then you enter its settings: number of trials, number of successes, number of events, number of defective items in the sample as appropriate.
Coming soon: average, fashion, minimum, maximum, the cumulative probability distribution, and the’confidence interval for the population mean to the confidence level chosen.
💡 It is this confidence interval that answers the practical question: I found 2 defective items out of 50—what can I say about the entire lot?
The answer is a range—often much wider than one might imagine—and this is an excellent argument for justifying a sample size.