Question: Suppose that of a population of N items, k are defective in some way. For example, the items might be documents, a small proportion of which are fraudulent. How large should a sample be so that with a specified probability it will contain at least one of the defective items? For example, if N = 10,000, k = 50, and p = .95, what should the sample size be? Such calculations are useful in planning sample sizes for acceptance sampling.