On estimating the size and confidence of a statistical audit
Javed A. Aslam, Raluca Ada Popa, Ronald L. Rivest · 2007
We consider the problem of statistical sampling for auditing elections, and we develop a remarkably simple and easily-calculated upper bound for the sample size necessary for determining with probability at least c if a given set of n objects contains fewer than b “bad ” objects. While the size of the optimal sample drawn without replacement can be determined with a computer program, our goal is to derive a highly accurate and simple formula that can be used by election officials equipped with only a hand-held calculator. We actually develop several formulae, but the one we recommend for use in practice is: U3(n, b, c) (b − 1) = n −