In a study of the relationship between creatinine excretion, height, and weight, the data shown in the following table were collected on 20 infant males:

Infant Creatinine Excretion

(mg/day)

Y Weight (kg)

X1 Height (cm)

X2 1 100 9 72 2 115 10 76 3 52 6 59 4 85 8 68 5 135 10 60 6 58 5 58 7 90 8 70 8 60 7 65 9 45 4 54 10 125 11 83 11 86 7 64 12 80 7 66 13 65 6 61 14 95 8 66 15 25 5 57 16 125 11 81 17 40 5 59 18 95 9 71 19 70 6 62 20 120 10 75

(a) Find the multiple regression equation describing the relationship among these variables.

(b) Compute R2 and do an analysis of variance.

(c) Let X1 ¼ 10 and X2 ¼ 60 and find the predicted value of Y.