Methods
The mean prediction estimation is consistent with theory (107.5 ± 6.1 mg Zn/kg; X ¯ ± SEM <math> <mrow><mover><mi>X</mi> <mo>¯</mo></mover> <mo>±</mo> <mtext>SEM</mtext></mrow> </math> ). When test or "unknown" samples are near the mean of the standard samples, the CI is smaller than when near the extremes of the calibration curve. When calibration curve error is small (R 2 > approximately 0.95), there is little advantage to using the Abductive Method, but when calibration curve error is larger, as in many bioassays with growing animals, the Abductive Method improves the accuracy of the CI calculations. The Abductive Method was used to demonstrate the influence of the number of replicate samples on experimental power and cost.