Biostatistics

528 CHAPTER 10 MULTIPLE REGRESSION AND CORRELATION
Infant
Creatinine
Excretion
(mg/day)
Y
Weight (kg)
X 1
Height (cm)
X 2
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 R 2 and do an analysis of variance.
(c) Let X 1 ¼ 10 and X 2 ¼ 60 and find the predicted value of Y.
9. A study was conducted to examine those variables thought to be related to the job satisfaction of
nonprofessional hospital employees. A random sample of 15 employees gave the following
results:
Score on Job
Satisfaction
Test (Y)
Coded
Intelligence
Score
(X 1 )
Index of
Personal
Adjustment
(X 2 )
54 15 8
37 13 1
30 15 1
48 15 7
37 10 4
37 14 2
31 8 3
49 12 7
43 1 9
12 3 1
30 15 1
37 14 2
61 14 10
31 9 1
31 4 5
(a) Find the multiple regression equation describing the relationship among these variables.
(b) Compute the coefficient of multiple determination and do an analysis of variance.
(c) Let X 1 ¼ 10 and X 2 ¼ 5 and find the predicted value of Y.
10. A medical research team obtained the index of adiposity, basal insulin, and basal glucose values on 21
normal subjects. The results are shown in the following table. The researchers wished to investigate
the strength of the association among these variables.