The distribution of sample means
figureposted on 30.12.2011, 13:58 authored by Elise Whitley, Jonathan Ball
Taken from "Statistics review 2: Samples and populations"
Critical Care 2002;6(2):143-148.
Published online 7 Feb 2002
Copyright © 2002 BioMed Central Ltd.The shaded area represents the range of values in which 95% of sample means lie. Confidence interval A is calculated from a sample with a mean that lies within this shaded area, and contains the true population mean. Confidence interval B, however, is calculated from a sample with a mean that falls outside the shaded area, and does not contain the population mean. SE = standard error.