Estimation of the percentage of a normal distribution lying outside a specified interval

Abstract

Point and interval estimation for the percentage of a normal population lying outside a specified Interval Is investigated. Resnikoff's (1955) confidence Interval procedure is shown to perform well when the percentage outside is small, and to be conservative otherwise.When the percentage to be estimated is large, an alternative interval is recommended.Monte Carlo studies show the sensitivity of these estimation procedures to violations of the normality assumption.Attempts to transform the sample to approximate normality prior to estimation were moderately successful in achieving robust estimation procedures.