A real estate developer is interested in determining the relation between family income
(X1), in thousand of dollars, family size (X2) and the combined years of formal education
for husband and wife (X3, years beyond high schools) for local residents. And the squared
footage of their houses (Y), measured in hundreds of square feet. A random sample of ten
families is obtained with the results presented below.
(The data was entered in columns 1 to 4 of Minitab worksheet. The following is the
printout presents the data:
y
16
17
26
24
22
21
32
18
30
20
x1
32
36
55
47
38
60
66
44
70
50
x2
2
2
3
4
4
3
6
3
5
3
x3
4
8
7
0
2
10
8
8
2
6
Perform the following:
(1) Plot the scatter diagram for Y and each of the all Xs and comment on the
plots.
(2) Compute the Pearson’s correlation coefficients for Y and each of the Xs and
interpret them.
(3) Estimate the regression of Y on X1, X2, and X2 and comment on it
(4) Validate the estimated model. (overall model, and each of its components)
(5) Re-estimate the final model and comment on it.
(6) Test whether B1=0 and estimate the 95% CI for B1.
(7) Predict the estimated value of Y when X1= 52, X2=5 and X3=16. Comment
on what does it mean?
Click here to go to the MINITAB data file: Multiple Regression Exercise