2016-07-262016-07-262010González Abril, L., Sánchez-Reyes Fernández, L.M. y Velasco Morente, F. (2010). Some commentaries on confidence intervals of the mean in a Normal population. Boletín de Estadística e Investigación Operativa, 26 (1), 19-24.1889-3805http://hdl.handle.net/11441/44033In this paper, a study on the length of confidence intervals of the mean in a Normal population when the variance is either known or unknown is carried out. It is also proved that ignoring the population variance always leads to a worse interval than when such a variance is taken into accountapplication/pdfengAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Student`s t populationChi-squared populationinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess