The fraction nonconforming is a key quality measure used in statistical quality control design in clinical laboratory medicine. The confidence bounds of normal populations of measurements for the fraction nonconforming each of the lower and upper quality specification limits when both the random and the systematic error are unknown can be calculated using the noncentral t-distribution, as it is described in detail and illustrated with examples.

翻译：不合格率是临床实验医学统计质量控制设计中使用的关键质量指标。当随机误差和系统误差均未知时，可通过非中心t分布计算测量值正态总体在上下质量规范界限各自对应的不合格率置信区间，本文对此进行了详细阐述并附实例说明。