# x07.txt # # Reference: # # D G Kleinbaum and L L Kupper, # Applied Regression Analysis and Other Multivariable Methods, # Duxbury Press, 1978, page 148. # # Helmut Spaeth, # Mathematical Algorithms for Linear Regression, # Academic Press, 1991, # ISBN 0-12-656460-4. # # Discussion: # # A psychiatrist assigns values for mental retardation and # degree of distrust of doctors in 53 newly hospitalized patients. # Six months later, a value for the degree of illness of each patient # is assigned. The question is whether the effect of treatment can # be related to these indices. Since the independent and dependent # variables are essentially subjective, it is assumed that large # errors are made in all of them. # # There are 53 rows of data. The data comprises: # # I, the index; # A1, the degree of mental retardation; # A2, the degree of distrust of doctors; # B, the degree of illness. # # We seek a model of the form: # # B = A1 * X1 + A2 * X2 # 4 columns 53 rows Index Retardation Index Distrust Index Degree of Illness after 6 Months 1 2.80 6.1 44 2 3.10 5.1 25 3 2.59 6.0 10 4 3.36 6.9 28 5 2.80 7.0 25 6 3.35 5.6 72 7 2.99 6.3 45 8 2.99 7.2 25 9 2.92 6.9 12 10 3.23 6.5 24 11 3.37 6.8 46 12 2.72 6.6 8 13 3.47 8.4 15 14 2.70 5.9 28 15 3.24 6.0 26 16 2.65 6.0 27 17 3.41 7.6 4 18 2.58 6.2 14 19 2.81 6.0 21 20 2.80 6.4 22 21 3.62 6.8 60 22 2.74 8.4 10 23 3.27 6.7 60 24 3.78 8.3 12 25 2.90 5.6 28 26 3.70 7.3 39 27 3.40 7.0 14 28 2.63 6.9 8 29 2.65 5.8 11 30 3.26 7.2 7 31 3.15 6.5 23 32 2.60 6.3 16 33 2.74 6.8 26 34 2.72 5.9 8 35 3.11 6.8 11 36 2.79 6.7 12 37 2.90 6.7 50 38 2.74 5.5 9 39 2.70 6.9 13 40 3.08 6.3 22 41 2.18 6.1 23 42 2.88 5.8 31 43 3.04 6.8 20 44 3.32 7.3 66 45 2.80 5.9 9 46 3.29 6.8 12 47 3.56 8.8 21 48 2.74 7.1 13 49 3.06 6.9 10 50 2.54 6.7 4 51 2.78 7.2 18 52 2.81 5.2 10 53 3.26 6.6 7