load("C:/Users/SANCHEZ/Desktop/GABRIEL2021/Universidad/Ciclo V/Econometria/datos_parcial.RData")

#a) Estime un modelo para explicar los ingresos usando todas las variables del datafrmae
modelo_ingresos<-lm(formula = income ~ sex+status+verbal+gamble,data = teengamb)
summary(modelo_ingresos)
## 
## Call:
## lm(formula = income ~ sex + status + verbal + gamble, data = teengamb)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -4.9561 -1.9072 -0.6399  1.1958  7.1716 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  4.41097    2.00311   2.202   0.0332 *  
## sex          0.09035    1.07210   0.084   0.9332    
## status      -0.06279    0.03250  -1.932   0.0601 .  
## verbal       0.24660    0.26492   0.931   0.3572    
## gamble       0.07214    0.01491   4.839 1.79e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 2.736 on 42 degrees of freedom
## Multiple R-squared:  0.4581, Adjusted R-squared:  0.4065 
## F-statistic: 8.877 on 4 and 42 DF,  p-value: 2.743e-05
#b) Calcule un intervalo de confianza de 92.5% para las variables "verbal" y "gamble" ¿hay evidencia que estas variables tienen una relación con los ingresos? Justifique
#Relación de "verbal"
confint(object = modelo_ingresos,parm = "verbal",level=.925)
##            3.75 %  96.25 %
## verbal -0.2370767 0.730284
#Relación de "gamble"
confint(object = modelo_ingresos,parm = "gamble",level=.925)
##            3.75 %    96.25 %
## gamble 0.04492279 0.09936007

Hay evidencia de que no hay una relación entre los ingresos y la variable “verbal”

#Hay evidencia de que hay una relación de que el aumento en una libra en la variable “gamble” en un 92.5% de las veces aumenta entre un 0.0449 y un 0.0099 libras de ingreso.

#¿Es el modelo estadíticamente significativo? #Respuesta: No, debido a que el modelo solo es capaz de explicar el 40% de las variaciones y hay variables que no tienen relación con la variable endógena, como se vio en el enunciado anterior con la variable “gamble”

#d) Calcule las matrices A, P y M
matriz_X<-model.matrix(modelo_ingresos)
matriz_XX<-t(matriz_X)%*%matriz_X
#Matriz A
matriz_A<-solve(matriz_XX)%*%t(matriz_X)
head(matriz_A, n=5)
##                         1             2             3             4
## (Intercept) -0.1074542196 -2.196091e-02  0.0166636550  0.1071925261
## sex          0.0809403937  2.485496e-02  0.0546438428  0.0478553863
## status       0.0012534153 -1.991280e-03  0.0004440685  0.0004276380
## verbal       0.0053215827  1.872697e-02 -0.0052703695 -0.0181905266
## gamble       0.0002006996 -7.513551e-05 -0.0001277504 -0.0001794904
##                         5             6             7             8
## (Intercept) -0.1997769992 -0.0727522830  0.0110981773  0.0763090842
## sex          0.1347212618  0.1132679914  0.0302292619  0.0407941868
## status       0.0034635069  0.0038310373 -0.0013910482 -0.0003046734
## verbal      -0.0012648221 -0.0192505672  0.0094674890 -0.0082880014
## gamble       0.0009505469  0.0001630467 -0.0001123584 -0.0001319919
##                         9            10           11            12
## (Intercept) -9.132914e-03  0.0510438018  0.087083036 -0.0167374281
## sex          7.097846e-02  0.0044914027  0.008412608  0.0746863721
## status       1.310899e-03 -0.0028179758 -0.002235133  0.0013552721
## verbal      -8.630958e-03  0.0151875447  0.005811670 -0.0083339400
## gamble      -5.318337e-06 -0.0002723699 -0.000352645  0.0001045391
##                        13            14            15            16
## (Intercept)  0.1122954976  0.0427185721  8.013897e-03 -0.0661198460
## sex          0.0466193386  0.0363050643  5.948747e-02  0.0526471984
## status       0.0006366292 -0.0007824209  6.139250e-04 -0.0005397676
## verbal      -0.0198458906  0.0002642055 -5.660552e-03  0.0131714735
## gamble      -0.0003366211 -0.0001287975 -4.449864e-05  0.0001457429
##                        17            18            19            20
## (Intercept) -2.216644e-02  0.1060634947 -0.1023807059  0.0221131282
## sex          2.495517e-02  0.0206515598  0.0734580723 -0.0765340704
## status      -1.990081e-03 -0.0015527499  0.0002687394 -0.0017679247
## verbal       1.873499e-02 -0.0028979217  0.0109476264  0.0186186633
## gamble      -7.216639e-05 -0.0001864832  0.0004610514 -0.0007211633
##                        21            22            23            24
## (Intercept)  0.0152089834  0.0345152010  0.1958013412 -0.0291030585
## sex         -0.0447872567 -0.0850854939 -0.0802570127  0.0408815616
## status       0.0003787218 -0.0023178283 -0.0005639444 -0.0003685991
## verbal       0.0029117935  0.0210463644 -0.0142140679 -0.0017495613
## gamble      -0.0006398261 -0.0007335052 -0.0011352375  0.0032214611
##                        25            26            27           28
## (Intercept) -0.0592784672  0.1381978266  0.1725078240  0.172387314
## sex          0.0186606021 -0.0982876341 -0.0423970407 -0.093464504
## status       0.0026809592 -0.0024110128  0.0013201849 -0.001817377
## verbal      -0.0086993474  0.0076124462 -0.0270967224 -0.001691181
## gamble       0.0005012544 -0.0009752689 -0.0006920167 -0.001028822
##                        29            30            31            32
## (Intercept)  9.295843e-02 -0.0024663744  0.2161879565  0.0629101208
## sex         -6.809038e-02 -0.0361688693 -0.0413678917 -0.0665863569
## status      -5.950436e-04  0.0004818602 -0.0012880897 -0.0029267690
## verbal      -8.492182e-05  0.0036021599 -0.0207144383  0.0163772489
## gamble      -8.638989e-04 -0.0003844818  0.0009339733  0.0004460091
##                       33            34            35           36            37
## (Intercept) -0.042460772 -0.0944339373  0.3669409465 -0.122887833 -0.0592784672
## sex         -0.010199698 -0.0286789161 -0.0871197168  0.021921773  0.0186606021
## status      -0.001356843  0.0005066856 -0.0001807799  0.001065153  0.0026809592
## verbal       0.014668633  0.0165785096 -0.0418510753  0.009033623 -0.0086993474
## gamble       0.001634588 -0.0003119579 -0.0012205537  0.001396874  0.0005012544
##                        38            39            40            41
## (Intercept)  0.0981624593  1.178992e-01  2.680957e-02  0.0190830379
## sex         -0.0635335936 -5.875763e-02 -5.578040e-03 -0.0769348096
## status      -0.0025781024  5.256039e-05  2.255456e-03 -0.0021083954
## verbal       0.0084881599 -9.027311e-03 -1.566188e-02  0.0209210901
## gamble       0.0004605131 -7.838416e-04 -5.180903e-05 -0.0005522725
##                        42            43            44            45
## (Intercept) -0.1583104849 -0.0583931945 -0.0348765429  0.0112423080
## sex          0.0176999260 -0.0007604938 -0.0393553283  0.0001342630
## status       0.0004787128  0.0023601921  0.0003553769  0.0019881420
## verbal       0.0183854152 -0.0036777773  0.0099241877 -0.0128697756
## gamble       0.0014682421 -0.0001187175 -0.0005234561  0.0002981982
##                        46            47
## (Intercept) -0.0097463601 -9.169014e-02
## sex         -0.0054909255 -8.523074e-03
## status       0.0023919320  1.283812e-03
## verbal      -0.0106339789  8.503092e-03
## gamble      -0.0002143037  8.876445e-05
#Matriz P
matriz_P<-matriz_X%*%matriz_A
head(matriz_P, n=5)
##            1          2          3          4          5            6
## 1 0.07998301 0.05115446 0.05179203 0.03133324 0.10146454  0.081894071
## 2 0.05115446 0.09695391 0.04157846 0.02149756 0.02180388 -0.006219786
## 3 0.05179203 0.04157846 0.05611581 0.06172736 0.05550509  0.066760684
## 4 0.03133324 0.02149756 0.06172736 0.09294939 0.03380216  0.071972723
## 5 0.10146454 0.02180388 0.05550509 0.03380216 0.16858435  0.138724307
##            7          8          9          10          11         12
## 1 0.04612389 0.03526092 0.05965372  0.03331880  0.02799721 0.06039630
## 2 0.07811800 0.04226840 0.02950305  0.09813224  0.07940528 0.02922504
## 3 0.04666359 0.05610235 0.05856305  0.04239537  0.04766574 0.05809037
## 4 0.03942783 0.07445687 0.06398805  0.03539376  0.05358429 0.06332394
## 5 0.02444699 0.02840845 0.07790206 -0.01147131 -0.01020649 0.08141908
##           13         14         15         16         17          18         19
## 1 0.03261580 0.04123382 0.05352713 0.06437099 0.05117453  0.02434144 0.07236409
## 2 0.01797333 0.05922950 0.03940685 0.07678565 0.09694640  0.06005469 0.06618308
## 3 0.06339477 0.05165930 0.05625328 0.04558479 0.04156568  0.05187578 0.04670648
## 4 0.09489956 0.05723245 0.06172422 0.02516368 0.02147962  0.07028504 0.02575825
## 5 0.03493084 0.02775549 0.06124991 0.05967081 0.02189893 -0.00105213 0.08516305
##             20           21           22           23          24           25
## 1  0.004364203  0.013030887 -0.000408619 -0.026929380 -0.02101654  0.026516276
## 2  0.045026472  0.004320285  0.052901431 -0.013958659 -0.01253876 -0.035145786
## 3 -0.008122178  0.001905195 -0.010051752  0.009393977 -0.01235703  0.006381542
## 4 -0.034712674 -0.011997619 -0.036638615  0.034610379  0.01797615  0.003310761
## 5 -0.034521545  0.005792400 -0.047234916 -0.057075257  0.03696371  0.073874292
##             26          27           28           29            30           31
## 1 -0.022151892 -0.01933357 -0.027292845 -0.006158543  0.0147569037 -0.056588016
## 2  0.033301403 -0.04969782  0.014506816  0.007527460  0.0036741201 -0.026961953
## 3 -0.003622605  0.01637729  0.001532789  0.002341911  0.0008065417  0.002874116
## 4 -0.004267845  0.05363735  0.013761140  0.001560685 -0.0135412365  0.062713805
## 5 -0.075021342 -0.01441450 -0.072901028 -0.031421573  0.0139671032 -0.056315395
##            32           33           34          35           36           37
## 1 -0.02192347 -0.004510398  0.035356189 -0.06420715  0.025625743  0.026516276
## 2  0.04539222  0.026696992  0.023702420 -0.06004921  0.001127216 -0.035145786
## 3 -0.01370320 -0.014851862 -0.004894429  0.02202592 -0.007353649  0.006381542
## 4 -0.01686091 -0.020045048 -0.044888911  0.09844505 -0.024810093  0.003310761
## 5 -0.05415645  0.008531726  0.036335412 -0.09066092  0.067916626  0.073874292
##              38           39          40           41          42           43
## 1 -0.0289490801 -0.010396348  0.01096476  0.001988784  0.03088712  0.031793891
## 2  0.0303472762 -0.011605237 -0.04091074  0.050481878  0.01987672 -0.022490528
## 3 -0.0098319656  0.006922429  0.01071213 -0.010335861 -0.01258569  0.006106756
## 4 -0.0002436178  0.018781964  0.02135858 -0.037234072 -0.04294677 -0.008646056
## 5 -0.0560164577 -0.025023797  0.04152569 -0.038353292  0.06636664  0.062509717
##             44           45           46           47
## 1  0.023285851  0.009813607  0.021679416  0.033285940
## 2  0.015112183 -0.035913659 -0.033335020  0.003758260
## 3 -0.001537801  0.007719170  0.009460326 -0.001693615
## 4 -0.028405798  0.017742290  0.007636479 -0.029606128
## 5  0.018001387  0.043492278  0.050966113  0.052999093
n<-nrow(matriz_X)
#Matriz M
matriz_M<-diag(n)-matriz_P
head(matriz_M, n=5)
##             1           2           3           4           5            6
## 1  0.92001699 -0.05115446 -0.05179203 -0.03133324 -0.10146454 -0.081894071
## 2 -0.05115446  0.90304609 -0.04157846 -0.02149756 -0.02180388  0.006219786
## 3 -0.05179203 -0.04157846  0.94388419 -0.06172736 -0.05550509 -0.066760684
## 4 -0.03133324 -0.02149756 -0.06172736  0.90705061 -0.03380216 -0.071972723
## 5 -0.10146454 -0.02180388 -0.05550509 -0.03380216  0.83141565 -0.138724307
##             7           8           9          10          11          12
## 1 -0.04612389 -0.03526092 -0.05965372 -0.03331880 -0.02799721 -0.06039630
## 2 -0.07811800 -0.04226840 -0.02950305 -0.09813224 -0.07940528 -0.02922504
## 3 -0.04666359 -0.05610235 -0.05856305 -0.04239537 -0.04766574 -0.05809037
## 4 -0.03942783 -0.07445687 -0.06398805 -0.03539376 -0.05358429 -0.06332394
## 5 -0.02444699 -0.02840845 -0.07790206  0.01147131  0.01020649 -0.08141908
##            13          14          15          16          17          18
## 1 -0.03261580 -0.04123382 -0.05352713 -0.06437099 -0.05117453 -0.02434144
## 2 -0.01797333 -0.05922950 -0.03940685 -0.07678565 -0.09694640 -0.06005469
## 3 -0.06339477 -0.05165930 -0.05625328 -0.04558479 -0.04156568 -0.05187578
## 4 -0.09489956 -0.05723245 -0.06172422 -0.02516368 -0.02147962 -0.07028504
## 5 -0.03493084 -0.02775549 -0.06124991 -0.05967081 -0.02189893  0.00105213
##            19           20           21           22           23          24
## 1 -0.07236409 -0.004364203 -0.013030887  0.000408619  0.026929380  0.02101654
## 2 -0.06618308 -0.045026472 -0.004320285 -0.052901431  0.013958659  0.01253876
## 3 -0.04670648  0.008122178 -0.001905195  0.010051752 -0.009393977  0.01235703
## 4 -0.02575825  0.034712674  0.011997619  0.036638615 -0.034610379 -0.01797615
## 5 -0.08516305  0.034521545 -0.005792400  0.047234916  0.057075257 -0.03696371
##             25           26          27           28           29            30
## 1 -0.026516276  0.022151892  0.01933357  0.027292845  0.006158543 -0.0147569037
## 2  0.035145786 -0.033301403  0.04969782 -0.014506816 -0.007527460 -0.0036741201
## 3 -0.006381542  0.003622605 -0.01637729 -0.001532789 -0.002341911 -0.0008065417
## 4 -0.003310761  0.004267845 -0.05363735 -0.013761140 -0.001560685  0.0135412365
## 5 -0.073874292  0.075021342  0.01441450  0.072901028  0.031421573 -0.0139671032
##             31          32           33           34          35           36
## 1  0.056588016  0.02192347  0.004510398 -0.035356189  0.06420715 -0.025625743
## 2  0.026961953 -0.04539222 -0.026696992 -0.023702420  0.06004921 -0.001127216
## 3 -0.002874116  0.01370320  0.014851862  0.004894429 -0.02202592  0.007353649
## 4 -0.062713805  0.01686091  0.020045048  0.044888911 -0.09844505  0.024810093
## 5  0.056315395  0.05415645 -0.008531726 -0.036335412  0.09066092 -0.067916626
##             37            38           39          40           41          42
## 1 -0.026516276  0.0289490801  0.010396348 -0.01096476 -0.001988784 -0.03088712
## 2  0.035145786 -0.0303472762  0.011605237  0.04091074 -0.050481878 -0.01987672
## 3 -0.006381542  0.0098319656 -0.006922429 -0.01071213  0.010335861  0.01258569
## 4 -0.003310761  0.0002436178 -0.018781964 -0.02135858  0.037234072  0.04294677
## 5 -0.073874292  0.0560164577  0.025023797 -0.04152569  0.038353292 -0.06636664
##             43           44           45           46           47
## 1 -0.031793891 -0.023285851 -0.009813607 -0.021679416 -0.033285940
## 2  0.022490528 -0.015112183  0.035913659  0.033335020 -0.003758260
## 3 -0.006106756  0.001537801 -0.007719170 -0.009460326  0.001693615
## 4  0.008646056  0.028405798 -0.017742290 -0.007636479  0.029606128
## 5 -0.062509717 -0.018001387 -0.043492278 -0.050966113 -0.052999093