Date of Award


Degree Type


Degree Name

Master of Science (MS)


Mathematics and Statistics

First Advisor

Donald V. Sisson

Second Advisor

Rex L. Hurst

Third Advisor

Frederick J. Post


Biological assays are essentially biological experiments. To compare the potencies of treatments on an agreed scale is generally of more interest than to compare the magnitude of effects of different treatments.

The relative potency, R = a/b, is defined as the ratio of the means of two equally effective doses where a is the mean of A and bis the mean of B. It is an estimate of the potency of one preparation, A, relative to that of the other, B.

Different procedures have been proposed to obtain the values of R and its confidence interval. Three of the these methods are compared and discussed here. They utilize the coefficient of variation, Fieller's theorem, and logarithms.