Let the amount of sales tax a retailer owes the govern- ment for a certain period. The article "Statistical Sampling in Tax Audits" (Statistics and the Law, 2008: 320-343) proposes modeling the uncertainty in 1 by regarding it as a normally distributed random variable with mean value and standard deviation or (in the article, these two parame- ters are estimated from the results of a tax audit involving n sampled transactions). If a represents the amount the retailer is assessed, then an under-assessment results if >a and an over-assessment results if a>