(I generally bottom post in newsgroups. See below. DW) [EMAIL PROTECTED] (Paul R Swank) wrote in 003601c28fd5$af678bc0$520e6a81@PEDUCT225:">news:003601c28fd5$af678bc0$520e6a81@PEDUCT225:
> The non-central t is symmetric. > > Paul R. Swank, Ph.D. > Professor, Developmental Pediatrics > Medical School > UT Health Science Center at Houston > > [EMAIL PROTECTED] (Alan McLean) wrote in > news:9391A1A0-FAE2- [EMAIL PROTECTED]: > >> This argument relies on the symmetry of the normal and t >> distributions - what happens with a confidence interval for a >> variance? >> > > Don't you need to consider the non-central T (which is not symmetric)? > > The CI for the variance is determined by the appropriate percentiles > of the (non-symmetric) chi. > > David Winsemius > I suggest you re-examine your belief: http://www.itl.nist.gov/div898/software/dataplot.html/distribu.htm and http://www.itl.nist.gov/div898/software/dataplot.html/refman2/auxillar/nctp df.pdf David Winsemius, MD, MPH . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
