SummaryA nomogram for confidence intervals and exceedance probabilities.In this paper two problems are considered regarding the probability β that an observation on a normally (μ, σ2)‐distributed random variable exceeds a given value W:If μ and σ2are unknown, the two problems are as follows:1)if Wis given, to determine a confidence interval for β and2)if β is given, to determine a confidence interval for W.For these two essentially equivalent problems graphs are given from which the confidence intervals can be determined. The graphs are given in terms of:and are based on an approximation for the distribution