MTB > # Gelman et al example - page 47 MTB > # estimating an unknown normal variance from football MTB > # spread data MTB > name c1 'chisqs' c2 'sigma2' c3 'sigma' MTB > rand 1000 'chisqs'; SUBC> chisq 672. MTB > let 'sigma2'=672*13.85**2/'chisqs' MTB > let 'sigma'=sqrt('sigma2') MTB > dotplot 'sigma' Each dot represents 4 points . ..: .: : : ::::::::: : ::.::::::::::::. ::::::::::::::::.. .:::::::::::::::::::.: . .:::::::::::::::::::::::::: . . ..:.:::::::::::::::::::::::::::::::..:. . +---------+---------+---------+---------+---------+-------sigma 12.50 13.00 13.50 14.00 14.50 15.00 MTB > notitle MTB > median 'sigma' Median of sigma = 13.861 MTB > sort 'sigma' 'sigma' MTB > let k1='sigma'(25) MTB > let k2='sigma'(975) MTB > prin k1 k2 K1 13.1937 K2 14.6357