Title 'Model Building using Backward Selection'.
Data list fixed records=1
	/1 gpa 1-3 greq 5-7 grev 9-11 mat 13-14 ar 16-18.
begin data
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
end data.
Regression variables=gpa,greq,grev,mat,ar
	/descriptives=mean,stddev,corr,n
	/statistics=r,anova,cha,coeff,ci,tol,history	
	/dependent= gpa
	/method=backward.







OUTPUT:



22 Dec 99   SPSS for Unix, Release 6.1 (AIX 3.2)                                                                              Page 1
14:08:54    UCLA OAC                       IBM RS6000       AIX 3.2.5/4.


For AIX 3.2.5/4.        UCLA OAC                                 SPSS ID 90095



                                     * * * *   M U L T I P L E   R E G R E S S I O N   * * * *


Listwise Deletion of Missing Data

             Mean  Std Dev  Label

GPA         3.313     .600
GREQ      565.333   48.618
GREV      575.333   83.034
MAT        67.000    9.248
AR          3.567     .838

N of Cases =    30

Correlation:

                GPA       GREQ       GREV        MAT         AR

GPA           1.000       .611       .581       .604       .621
GREQ           .611      1.000       .468       .267       .508
GREV           .581       .468      1.000       .426       .405
MAT            .604       .267       .426      1.000       .525
AR             .621       .508       .405       .525      1.000


22 Dec 99   Model Building using Backward Selection                                                                           Page 3
14:08:54    UCLA OAC                       IBM RS6000       AIX 3.2.5/4.


                                     * * * *   M U L T I P L E   R E G R E S S I O N   * * * *

Equation Number 1    Dependent Variable..   GPA

  Descriptive Statistics are printed on Page    2

Block Number  1.  Method:  Enter


Variable(s) Entered on Step Number  1..    AR
                                    2..    GREV
                                    3..    MAT
                                    4..    GREQ


Multiple R           .80030                                             Analysis of Variance
R Square             .64047          R Square Change    .64047                              DF      Sum of Squares      Mean Square
Adjusted R Square    .58295          F Change         11.13400          Regression           4             6.68313          1.67078
Standard Error       .38738          Signif F Change    .0000           Residual            25             3.75153           .15006

                                                                        F =      11.13400       Signif F =  .0000


------------------------------------------ Variables in the Equation ------------------------------------------

Variable              B        SE B     95% Confdnce Intrvl B       Beta  Tolerance        VIF         T  Sig T

GREQ            .003998     .001831  2.27987E-04      .007769    .324062    .653236      1.531     2.184  .0385
GREV            .001524     .001050 -6.39208E-04      .003687    .210912    .680518      1.469     1.451  .1593
MAT             .020896     .009549      .001230      .040562    .322145    .663614      1.507     2.188  .0382
AR              .144234     .113001     -.088497      .376964    .201604    .576442      1.735     1.276  .2135
(Constant)    -1.738107     .950740    -3.696192      .219979                                     -1.828  .0795


End Block Number   1   All requested variables entered.

22 Dec 99   Model Building using Backward Selection                                                                           Page 4
14:08:54    UCLA OAC                       IBM RS6000       AIX 3.2.5/4.


                                     * * * *   M U L T I P L E   R E G R E S S I O N   * * * *

Equation Number 1    Dependent Variable..   GPA

Block Number  2.  Method:  Backward     Criterion   POUT  .1000


Variable(s) Removed on Step Number  5..    AR


Multiple R           .78552                                             Analysis of Variance
R Square             .61704          R Square Change   -.02343                              DF      Sum of Squares      Mean Square
Adjusted R Square    .57286          F Change          1.62917          Regression           3             6.43866          2.14622
Standard Error       .39204          Signif F Change    .2135           Residual            26             3.99601           .15369

                                                                        F =      13.96436       Signif F =  .0000


------------------------------------------ Variables in the Equation ------------------------------------------

Variable              B        SE B     95% Confdnce Intrvl B       Beta  Tolerance        VIF         T  Sig T

GREQ            .004926     .001701      .001430      .008421    .399215    .775329      1.290     2.896  .0076
GREV            .001612     .001060 -5.67631E-04      .003792    .223171    .683502      1.463     1.520  .1405
MAT             .026119     .008731      .008172      .044067    .402666    .812902      1.230     2.991  .0060
(Constant)    -2.148770     .905406    -4.009858     -.287682                                     -2.373  .0253


----------- not in ------------

Variable   Tolerance        VIF

AR           .576442      1.735



                                     * * * * * * * * * * * * * * * * * * * * * * * * * * * * *


Variable(s) Removed on Step Number  6..    GREV


Multiple R           .76355                                             Analysis of Variance
R Square             .58300          R Square Change   -.03404                              DF      Sum of Squares      Mean Square
Adjusted R Square    .55211          F Change          2.31121          Regression           2             6.08344          3.04172
Standard Error       .40144          Signif F Change    .1405           Residual            27             4.35122           .16116

                                                                        F =      18.87433       Signif F =  .0000

22 Dec 99   Model Building using Backward Selection                                                                           Page 5
14:08:54    UCLA OAC                       IBM RS6000       AIX 3.2.5/4.


                                     * * * *   M U L T I P L E   R E G R E S S I O N   * * * *

Equation Number 1    Dependent Variable..   GPA


------------------------------------------ Variables in the Equation ------------------------------------------

Variable              B        SE B     95% Confdnce Intrvl B       Beta  Tolerance        VIF         T  Sig T

GREQ            .005976     .001591      .002712      .009241    .484382    .928761      1.077     3.756  .0008
MAT             .030807     .008365      .013645      .047970    .474943    .928761      1.077     3.683  .0010
(Constant)    -2.129377     .927038    -4.031501     -.227253                                     -2.297  .0296


----------- not in ------------

Variable   Tolerance        VIF

GREV         .683502      1.463
AR           .578970      1.727


End Block Number   2   POUT =     .100 Limits reached.



                                     * * * * * * * * * * * * * * * * * * * * * * * * * * * * *


                                                       Summary table
                                                       -------------

Step   MultR     Rsq  AdjRsq    F(Eqn)  SigF   RsqCh       FCh SigCh       Variable  BetaIn  Correl
   1                                                                  In:  AR         .6207   .6207
   2                                                                  In:  GREV       .3947   .5815
   3                                                                  In:  MAT        .2900   .6042
   4   .8003   .6405   .5829    11.134  .000   .6405    11.134  .000  In:  GREQ       .3241   .6111
   5   .7855   .6170   .5729    13.964  .000  -.0234     1.629  .214 Out:  AR                 .6207
   6   .7635   .5830   .5521    18.874  .000  -.0340     2.311  .141 Out:  GREV               .5815

22 Dec 99   Model Building using Backward Selection                                                                           Page 6
14:08:54    UCLA OAC                       IBM RS6000       AIX 3.2.5/4.


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