Abstract: In this paper we study the asymptotic properties of the sequential risk-efficient rule developed for the estimation of the mean of the logistic response function based on the quantal responses observed at equally spaced dose levels. The Spearman-Karber (S-K) and Spearman-type variance (S- T-V) estimator are used for the mean and variance, respectively, in the sequential estimation.
Key words and phrases: Logistic regression, lethal dosage 50, sequential estimation, Spearman-Karber estimator, optimal properties.