Dispersion: Range Difference between minimum and maximum values (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Mean Deviation Mean difference from the mean Easy to understand Difficult to handle in modeling (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Variance Average of the squares of difference from the mean Second moment Giving penalty for large deviations (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Variance Short-cut formulae (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Standard Deviation Square root of variance Compare to absolute deviation (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: 3-21on p. 124 Y Y-µ (Y-µ)^2 Y^2 10 -25 625 100 60 25 3600 50 15 225 2500 30 -5 900 40 5 1600 20 -15 400 210 1750 9100 Sum: 210; mean: 35 = 210/6 (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Computation1 N=6; µ=35, Ʃ(y-µ)^2= 1750; Ʃy^2=9100 Variance using the standard formula (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Computation2 N=6; µ=35, Ʃy^2=9100 Variance using the short-cut (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Computation3 N=6; Ʃy=210; µ=35, Ʃy^2=9100 Variance using the short-cut in textbook (c) 2007 IUPUI SPEA K300 (4392)
Dispersion: Computation4 σ^2=291.7, s^2=350, Ʃ(y-µ)^2= 1750 Compute standard deviation (c) 2007 IUPUI SPEA K300 (4392)