[SAS Program]              
               
data rsq;
input gpa greq grev mat ar;
cards;
3.2 625 540 65 2.7
4.1 575 680 75 4.5
3.0 520 480 65 2.5
2.6 545 520 55 3.1
3.7 520 490 75 3.6
4.0 655 535 65 4.3
4.3 630 720 75 4.6
2.7 500 500 75 3.0
3.6 605 575 65 4.7
4.1 555 690 75 3.4
2.7 505 545 55 3.7
2.9 540 515 55 2.6
2.5 520 520 55 3.1
3.0 585 710 65 2.7
3.3 600 610 85 5.0
3.2 625 540 65 2.7
4.1 575 680 75 4.5
3.0 520 480 65 2.5
2.6 545 520 55 3.1
3.7 520 490 75 3.6
4.0 655 535 65 4.3
4.3 630 720 75 4.6
2.7 500 500 75 3.0
3.6 605 575 65 4.7
4.1 555 690 75 3.4
2.7 505 545 55 3.7
2.9 540 515 55 2.6
2.5 520 520 55 3.1
3.0 585 710 65 2.7
3.3 600 610 85 5.0
;
proc reg;
  model gpa = greq grev mat ar / selection=forward;
run;

[SAS Output]

The SAS System                                08:34 Friday, January 29, 1999   1

Forward Selection Procedure for Dependent Variable GPA

Step 1   Variable AR Entered        R-square = 0.38529398   C(p) = 16.74420939

                DF         Sum of Squares      Mean Square          F   Prob>F

Regression       1             4.02041421       4.02041421      17.55   0.0003
Error           28             6.41425245       0.22908044
Total           29            10.43466667

                Parameter        Standard          Type II
Variable         Estimate           Error   Sum of Squares          F   Prob>F

INTERCEP       1.72944408      0.38804679       4.55022494      19.86   0.0001
AR             0.44408110      0.10600367       4.02041421      17.55   0.0003

Bounds on condition number:            1,            1
--------------------------------------------------------------------------------

Step 2   Variable GREV Entered      R-square = 0.51549156   C(p) =  9.69078781

                DF         Sum of Squares      Mean Square          F   Prob>F

Regression       2             5.37898260       2.68949130      14.36   0.0001
Error           27             5.05568407       0.18724756
Total           29            10.43466667

                Parameter        Standard          Type II
Variable         Estimate           Error   Sum of Squares          F   Prob>F

INTERCEP       0.49717794      0.57651557       0.13925724       0.74   0.3961
GREV           0.00285138      0.00105858       1.35856839       7.26   0.0120
AR             0.32962504      0.10483495       1.85116176       9.89   0.0040

Bounds on condition number:     1.196581,     4.786325
--------------------------------------------------------------------------------

Step 3   Variable MAT Entered       R-square = 0.57187378   C(p) =  7.77019304

                DF         Sum of Squares      Mean Square          F   Prob>F

Regression       3             5.96731222       1.98910407      11.58   0.0001
Error           26             4.46735444       0.17182132
Total           29            10.43466667

                Parameter        Standard          Type II
Variable         Estimate           Error   Sum of Squares          F   Prob>F

INTERCEP      -0.14410465      0.65199045       0.00839364       0.05   0.8268
GREV           0.00231735      0.00105430       0.83009542       4.83   0.0371
MAT            0.01881259      0.01016662       0.58832962       3.42   0.0756
AR             0.24217230      0.11098884       0.81802648       4.76   0.0383

Bounds on condition number:     1.491861,     12.74089
--------------------------------------------------------------------------------


Step 4   Variable GREQ Entered      R-square = 0.64047409   C(p) =  5.00000000

                DF         Sum of Squares      Mean Square          F   Prob>F

Regression       4             6.68313369       1.67078342      11.13   0.0001
Error           25             3.75153298       0.15006132
Total           29            10.43466667

                Parameter        Standard          Type II
Variable         Estimate           Error   Sum of Squares          F   Prob>F

INTERCEP      -1.73810660      0.95073990       0.50153141       3.34   0.0795
GREQ           0.00399829      0.00183065       0.71582146       4.77   0.0385
GREV           0.00152365      0.00105016       0.31588005       2.11   0.1593
MAT            0.02089606      0.00954884       0.71861483       4.79   0.0382
AR             0.14423354      0.11300126       0.24447515       1.63   0.2135

Bounds on condition number:     1.734779,     24.96795
--------------------------------------------------------------------------------

All variables have been entered into the model.

Summary of Forward Selection Procedure for Dependent Variable GPA

        Variable   Number   Partial     Model
Step    Entered        In      R**2      R**2        C(p)           F   Prob>F

   1    AR              1    0.3853    0.3853     16.7442     17.5502   0.0003
   2    GREV            2    0.1302    0.5155      9.6908      7.2555   0.0120
   3    MAT             3    0.0564    0.5719      7.7702      3.4241   0.0756
   4    GREQ            4    0.0686    0.6405      5.0000      4.7702   0.0385