00000nam 2200000zi 4500 9.870432 CaOODSP 20241203113647 m o d f cr ||||||||||| 190322e198708##oncbd #ob f000 0 eng d CaOODSP eng rda CaOODSP eng fre n-cn-on En13-5/87-141E-PDF El-Shaarawi, A. H., author. Inferences about the mean from censored water quality data / by A.H. El-Shaarawi. Burlington, Ontario : National Water Research Institute, Canada Centre for Inland Waters, August 1987. 1 online resource (13 pages, 7 unnumbered pages) : maps, graphs. text txt rdacontent computer c rdamedia online resource cr rdacarrier NWRI contribution ; 87-141 "RRB-87-38." Title from cover. Digitized edition from print [produced by Environment and Climate Change Canada]. Includes bibliographical references. "Several methods which are commonly used for making inferences about the levels of many metals and organic contaminants in ambient waters from type I censored data are critically evaluated and their applications are illustrated using the concentrations of PCB in water samples from the Niagara River. Difficulties encountered in the application of all the methods, except the method of maximum likelihood, include the occurrence of inadmissible estimates for the censored values and the unavailability of the standard errors for these estimates. Under the assumption that the distribution of the data is lognormal, the log regression method is modified to produce admissible estimates of the censored values and the properties of the maximum likelihood estimates for the lognormal mean are derived. Furthermore, an approximate confidence interval for the lognormal mean is given and its use for estimating the load to and from the Niagara River is illustrated"--Abstract. Includes a management perspective and abstract in English and French. gccst Water pollution gccst Water quality gccst Methodology Canada. Environment Canada. Canada Centre for Inland Waters. National Water Research Institute (Canada) NWRI contribution ; 87-141. (CaOODSP)9.844121 PDF 1.12 MB https://publications.gc.ca/collections/collection_2019/eccc/en13-5/En13-5-87-141-eng.pdf