load(file="workspace2.rdata")

summary(fitcool2)

Call:
lm(formula = cGPA ~ sleephrsday + I(sleephrsday^2) + studyhrsday + 
    I(studyhrsday^2) + I(studyhrsday^3) + I(studyhrsday^4) + 
    I(studyhrsday^5) + I(studyhrsday^6) + avgau + I(avgau^2) + 
    I(avgau^3) + I(avgau^4) + targetmingpa + I(targetmingpa^2) + 
    I(targetmingpa^3) + I(targetmingpa^4))

Residuals:
     Min       1Q   Median       3Q      Max 
-0.64111 -0.20894  0.06135  0.17735  0.72014 

Coefficients: (1 not defined because of singularities)
                    Estimate Std. Error t value Pr(>|t|)  
(Intercept)        7.595e+01  5.891e+01   1.289   0.2075  
sleephrsday        8.370e-01  5.938e-01   1.410   0.1693  
I(sleephrsday^2)  -5.435e-02  4.798e-02  -1.133   0.2666  
studyhrsday        5.205e+00  2.589e+00   2.010   0.0538 .
I(studyhrsday^2)  -2.201e+00  1.325e+00  -1.662   0.1073  
I(studyhrsday^3)   4.712e-01  3.294e-01   1.431   0.1632  
I(studyhrsday^4)  -5.465e-02  4.221e-02  -1.295   0.2057  
I(studyhrsday^5)   3.258e-03  2.669e-03   1.221   0.2320  
I(studyhrsday^6)  -7.776e-05  6.569e-05  -1.184   0.2461  
avgau             -4.143e+00  6.236e+00  -0.664   0.5117  
I(avgau^2)         4.570e-01  5.818e-01   0.785   0.4386  
I(avgau^3)        -2.112e-02  2.358e-02  -0.896   0.3777  
I(avgau^4)         3.482e-04  3.504e-04   0.994   0.3286  
targetmingpa      -5.523e+01  3.970e+01  -1.391   0.1748  
I(targetmingpa^2)  1.464e+01  1.040e+01   1.408   0.1698  
I(targetmingpa^3) -1.251e+00  9.013e-01  -1.388   0.1758  
I(targetmingpa^4)         NA         NA      NA       NA  
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 0.365 on 29 degrees of freedom
Multiple R-squared:  0.8336,	Adjusted R-squared:  0.7475 
F-statistic: 9.683 on 15 and 29 DF,  p-value: 1.388e-07

predict(fitcool2, data.frame(sleephrsday=8,studyhrsday=6,avgau=9.8,targetmingpa=4.5),interval="confidence",level=0.75)

Warning message in predict.lm(fitcool2, data.frame(sleephrsday = 8, studyhrsday = 6, :
“prediction from a rank-deficient fit may be misleading”

fitcool3 = lm(cGPA~sleephrsday+I(sleephrsday^2)+studyhrsday+I(studyhrsday^2)+I(studyhrsday^3)+I(studyhrsday^4)+I(studyhrsday^5)+I(studyhrsday^6)+avgau+I(avgau^2)+I(avgau^3)+I(avgau^4)+motivate+I(motivate^2)+I(motivate^3)+targetmingpa+I(targetmingpa^2)+I(targetmingpa^3)+I(targetmingpa^4)+workhrsweek+I(workhrsweek^2)+I(workhrsweek^3)+I(workhrsweek^4))
summary(fitcool3)

Call:
lm(formula = cGPA ~ sleephrsday + I(sleephrsday^2) + studyhrsday + 
    I(studyhrsday^2) + I(studyhrsday^3) + I(studyhrsday^4) + 
    I(studyhrsday^5) + I(studyhrsday^6) + avgau + I(avgau^2) + 
    I(avgau^3) + I(avgau^4) + motivate + I(motivate^2) + I(motivate^3) + 
    targetmingpa + I(targetmingpa^2) + I(targetmingpa^3) + I(targetmingpa^4) + 
    workhrsweek + I(workhrsweek^2) + I(workhrsweek^3) + I(workhrsweek^4))

Residuals:
     Min       1Q   Median       3Q      Max 
-0.59536 -0.19057  0.06449  0.16885  0.69697 

Coefficients: (5 not defined because of singularities)
                    Estimate Std. Error t value Pr(>|t|)
(Intercept)        9.549e+01  6.829e+01   1.398    0.174
sleephrsday        7.599e-01  6.432e-01   1.181    0.248
I(sleephrsday^2)  -4.814e-02  5.167e-02  -0.932    0.360
studyhrsday        4.699e+00  2.902e+00   1.619    0.117
I(studyhrsday^2)  -1.935e+00  1.496e+00  -1.294    0.207
I(studyhrsday^3)   4.080e-01  3.707e-01   1.101    0.281
I(studyhrsday^4)  -4.703e-02  4.719e-02  -0.996    0.328
I(studyhrsday^5)   2.805e-03  2.963e-03   0.947    0.353
I(studyhrsday^6)  -6.721e-05  7.251e-05  -0.927    0.363
avgau             -4.565e+00  6.629e+00  -0.689    0.497
I(avgau^2)         4.962e-01  6.155e-01   0.806    0.427
I(avgau^3)        -2.268e-02  2.485e-02  -0.913    0.370
I(avgau^4)         3.708e-04  3.682e-04   1.007    0.323
motivate          -3.821e-01  1.329e+00  -0.288    0.776
I(motivate^2)      7.688e-02  4.611e-01   0.167    0.869
I(motivate^3)     -4.194e-03  4.892e-02  -0.086    0.932
targetmingpa      -6.864e+01  4.804e+01  -1.429    0.165
I(targetmingpa^2)  1.817e+01  1.262e+01   1.440    0.162
I(targetmingpa^3) -1.559e+00  1.097e+00  -1.421    0.167
I(targetmingpa^4)         NA         NA      NA       NA
workhrsweek               NA         NA      NA       NA
I(workhrsweek^2)          NA         NA      NA       NA
I(workhrsweek^3)          NA         NA      NA       NA
I(workhrsweek^4)          NA         NA      NA       NA

Residual standard error: 0.3807 on 26 degrees of freedom
Multiple R-squared:  0.8376,	Adjusted R-squared:  0.7252 
F-statistic: 7.452 on 18 and 26 DF,  p-value: 3.015e-06

predict(fitcool3, data.frame(sleephrsday=6,studyhrsday=5,avgau=17,motivate=3,targetmingpa=3,workhrsweek=0),interval="confidence",level=0.75)

Warning message in predict.lm(fitcool3, data.frame(sleephrsday = 6, studyhrsday = 5, :
“prediction from a rank-deficient fit may be misleading”