Small sample likelihood inference for the ratio of means
The small sample likelihood inference method (Barndorff-Nielsen and Cox, 1994) is applied to Fieller's problem for normal distributions with unknown unequal variances and extended to non-normal distributions. The proposed method is applied to a bioequivalence study of two formulations of a drug product. Examples and simulation studies show that the proposed method for the ratio of means demonstrates essentially exact coverage probabilities even for small samples.
ratio of means ancillary fieller's interval r? -formula r? r? signed log-likelihood ratio statistic