Ejercicio 1

##numeral 1

options(scipen=9999)
load("C:/Users/MINEDUCYT/Downloads/modelo_ventas.RData")
# obtener la matrix X
matriz_X <- model.matrix(modelo_ventas)
#matrix XX
matriz_XX <- t(matriz_X)%*%matriz_X
#matriz A
matriz_A <- solve(matriz_XX)%*%t(matriz_X)

#matriz P
matriz_P <- matriz_X%*%matriz_A

#matriz M
#conocer numero de filas
n<-nrow(matriz_X)
#hacer la matriz M
matriz_M <-diag(n) - matriz_P

Numeral 2

#residuos del modelo (objeto 1)
residuos_modelo_ventas <- modelo_ventas$residuals
datos_modelo <-modelo_ventas$model
#residuos matriz (objeto 2)
residuos_matrices <- matriz_M%*%datos_modelo$ventas
#verificar
 cbind(residuos_modelo_ventas,residuos_matrices,residuos_modelo_ventas-residuos_matrices) |>  round(digits = 2) |>  as.data.frame()-> comparacion 
#agrgar nombre
names(comparacion) <- c("por matrices","En modelo","Diferencia")
comparacion
##     por matrices En modelo Diferencia
## 1         -15.93    -15.93          0
## 2          19.33     19.33          0
## 3          38.02     38.02          0
## 4         -15.43    -15.43          0
## 5           5.16      5.16          0
## 6          80.22     80.22          0
## 7         -16.35    -16.35          0
## 8         -22.89    -22.89          0
## 9         -34.40    -34.40          0
## 10         46.09     46.09          0
## 11        -40.56    -40.56          0
## 12          9.25      9.25          0
## 13          5.82      5.82          0
## 14        -19.64    -19.64          0
## 15         -2.74     -2.74          0
## 16        -20.58    -20.58          0
## 17         -4.89     -4.89          0
## 18         -0.83     -0.83          0
## 19        -36.61    -36.61          0
## 20         -8.11     -8.11          0
## 21         11.00     11.00          0
## 22         56.50     56.50          0
## 23         -7.55     -7.55          0
## 24         31.71     31.71          0
## 25        -40.48    -40.48          0
## 26         86.80     86.80          0
## 27         -1.44     -1.44          0
## 28         35.92     35.92          0
## 29         24.51     24.51          0
## 30        -38.94    -38.94          0
## 31         25.44     25.44          0
## 32        -17.24    -17.24          0
## 33        -44.11    -44.11          0
## 34         47.62     47.62          0
## 35        -38.06    -38.06          0
## 36        104.56    104.56          0
## 37        -22.01    -22.01          0
## 38          6.26      6.26          0
## 39        -20.85    -20.85          0
## 40         -8.14     -8.14          0
## 41          3.52      3.52          0
## 42          7.13      7.13          0
## 43         39.33     39.33          0
## 44         29.22     29.22          0
## 45        -13.40    -13.40          0
## 46          8.21      8.21          0
## 47        -42.24    -42.24          0
## 48        -15.16    -15.16          0
## 49         36.15     36.15          0
## 50        -42.33    -42.33          0
## 51         29.60     29.60          0
## 52        -27.94    -27.94          0
## 53        -25.78    -25.78          0
## 54        -16.15    -16.15          0
## 55         20.52     20.52          0
## 56        -34.10    -34.10          0
## 57         32.84     32.84          0
## 58         -8.84     -8.84          0
## 59        -25.90    -25.90          0
## 60          4.38      4.38          0
## 61        -56.13    -56.13          0
## 62         -5.97     -5.97          0
## 63         34.06     34.06          0
## 64        -22.00    -22.00          0
## 65        -22.92    -22.92          0
## 66        -33.91    -33.91          0
## 67        -25.98    -25.98          0
## 68        -24.10    -24.10          0
## 69         15.18     15.18          0
## 70        -12.96    -12.96          0
## 71         -2.78     -2.78          0
## 72        -39.34    -39.34          0
## 73          9.10      9.10          0
## 74        -23.58    -23.58          0
## 75         16.53     16.53          0
## 76         41.92     41.92          0
## 77        -61.13    -61.13          0
## 78        -11.80    -11.80          0
## 79         42.30     42.30          0
## 80        -28.28    -28.28          0
## 81        -18.10    -18.10          0
## 82         55.90     55.90          0
## 83        -32.84    -32.84          0
## 84          1.99      1.99          0
## 85         -7.85     -7.85          0
## 86          2.06      2.06          0
## 87        -18.80    -18.80          0
## 88        -12.42    -12.42          0
## 89        -34.44    -34.44          0
## 90         -0.71     -0.71          0
## 91        -19.86    -19.86          0
## 92        -71.04    -71.04          0
## 93          5.47      5.47          0
## 94         -1.83     -1.83          0
## 95        -22.68    -22.68          0
## 96         -9.60     -9.60          0
## 97         30.46     30.46          0
## 98          2.80      2.80          0
## 99         -1.39     -1.39          0
## 100        -6.92     -6.92          0
## 101        47.13     47.13          0
## 102        13.67     13.67          0
## 103        74.24     74.24          0
## 104         8.29      8.29          0
## 105         5.20      5.20          0
## 106       -23.16    -23.16          0
## 107       -39.16    -39.16          0
## 108       -36.55    -36.55          0
## 109       -51.39    -51.39          0
## 110        14.93     14.93          0
## 111        31.77     31.77          0
## 112         0.85      0.85          0
## 113         3.55      3.55          0
## 114        20.05     20.05          0
## 115         1.25      1.25          0
## 116        -6.04     -6.04          0
## 117        -5.24     -5.24          0
## 118       -59.49    -59.49          0
## 119        -9.08     -9.08          0
## 120       -15.33    -15.33          0
## 121       -22.74    -22.74          0
## 122        -6.98     -6.98          0
## 123        52.60     52.60          0
## 124        -7.38     -7.38          0
## 125         6.99      6.99          0
## 126       -36.29    -36.29          0
## 127        51.55     51.55          0
## 128       -45.71    -45.71          0
## 129       -38.99    -38.99          0
## 130       -49.74    -49.74          0
## 131       137.77    137.77          0
## 132        68.15     68.15          0
## 133        29.49     29.49          0
## 134         4.04      4.04          0
## 135         2.44      2.44          0
## 136        24.96     24.96          0
## 137        14.83     14.83          0
## 138        18.65     18.65          0
## 139       -13.45    -13.45          0
## 140       -17.13    -17.13          0
## 141       -36.00    -36.00          0
## 142        -7.79     -7.79          0
## 143        -5.46     -5.46          0
## 144       -38.02    -38.02          0
## 145       -33.90    -33.90          0
## 146        -7.02     -7.02          0
## 147        57.02     57.02          0
## 148       -24.42    -24.42          0
## 149         5.76      5.76          0
## 150       -21.33    -21.33          0
## 151        60.96     60.96          0
## 152       -37.40    -37.40          0
## 153         3.70      3.70          0
## 154       -11.53    -11.53          0
## 155         5.57      5.57          0
## 156        20.34     20.34          0
## 157        -6.39     -6.39          0
## 158         0.10      0.10          0
## 159        35.21     35.21          0
## 160       -12.86    -12.86          0
## 161        -0.28     -0.28          0
## 162        -5.49     -5.49          0
## 163         7.07      7.07          0
## 164       -11.48    -11.48          0
## 165       -17.07    -17.07          0
## 166        43.48     43.48          0
## 167        30.49     30.49          0
## 168        32.76     32.76          0
## 169         9.33      9.33          0
## 170        79.25     79.25          0
## 171       -32.15    -32.15          0
## 172        -2.32     -2.32          0
## 173       -19.07    -19.07          0
## 174        11.45     11.45          0
## 175        56.81     56.81          0
## 176       -20.90    -20.90          0
## 177        10.72     10.72          0
## 178        10.72     10.72          0
## 179        99.16     99.16          0
## 180         0.68      0.68          0
## 181         8.07      8.07          0
## 182        43.24     43.24          0
## 183       -53.93    -53.93          0
## 184       -14.41    -14.41          0
## 185        33.06     33.06          0
## 186       -26.80    -26.80          0
## 187       -11.78    -11.78          0
## 188         2.02      2.02          0
## 189        75.55     75.55          0
## 190       -31.29    -31.29          0
## 191        11.46     11.46          0
## 192       -34.64    -34.64          0
## 193       -47.21    -47.21          0
## 194       -20.94    -20.94          0
## 195       -16.29    -16.29          0
## 196       -54.55    -54.55          0
## 197       -31.98    -31.98          0
## 198         8.34      8.34          0
## 199        -9.58     -9.58          0
## 200        49.59     49.59          0

numeral 3

eigen(x = matriz_XX, symmetric = TRUE) -> descomposicion
auto_valores <- descomposicion$values
print(auto_valores)
## [1] 311421698.6388     70252.5341     40973.4590      3714.3627        12.7735
print(auto_valores > 0)
## [1] TRUE TRUE TRUE TRUE TRUE

#Ejercicio 2 Literal 1

load("C:/Users/MINEDUCYT/Downloads/datos_cajas.RData")
modelo_cajas <-lm(formula = Tiempo ~ Distancia+N_cajas, data= datos_cajas)
summary(modelo_cajas)
## 
## Call:
## lm(formula = Tiempo ~ Distancia + N_cajas, data = datos_cajas)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -9.2716 -0.5405  0.5212  1.4051  2.9381 
## 
## Coefficients:
##             Estimate Std. Error t value  Pr(>|t|)    
## (Intercept)   2.3112     5.8573   0.395   0.70007    
## Distancia     0.4559     0.1468   3.107   0.00908 ** 
## N_cajas       0.8772     0.1530   5.732 0.0000943 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 3.141 on 12 degrees of freedom
## Multiple R-squared:  0.7368, Adjusted R-squared:  0.6929 
## F-statistic:  16.8 on 2 and 12 DF,  p-value: 0.0003325

Numeral 2

#matriz X
matriz_X2 <- model.matrix(modelo_cajas)
#matriz XX
matriz_XX2 <-t(matriz_X2)%*%matriz_X2
#Matriz A
matriz_A2 <- solve(matriz_XX2)%*%t(matriz_X2)
#Matriz P
Matriz_P2 <- matriz_X2%*%matriz_A2 #alternativamente se puede matriz_P2<-matriz_X%*%solve(matriz_XX)%*%t(matriz_X)
#matriz M
n2 <-nrow(matriz_X2)
matriz_M2 <- diag(n2)-Matriz_P2

numeral 3

library(matlib)
## Warning: package 'matlib' was built under R version 4.5.2
#residuos del modelo
residuos_modelo2 <-modelo_cajas$residuals
matriz_y <-datos_cajas$Tiempo
#residuos de la matriz
residuos_por_matrices2 <-matriz_M2%*%matriz_y
# unir columnas (comparativa)
cbind(residuos_modelo2,
      residuos_por_matrices2,
      residuos_por_matrices2-residuos_por_matrices2) |>  as.data.frame() |>  round(digits=2) ->comparativa2

names(comparativa2) <- c("residuos modelo",
                         "residuos matrices",
                         "diferencia") 
print(comparativa2)
##    residuos modelo residuos matrices diferencia
## 1            -0.76             -0.76          0
## 2             0.13              0.13          0
## 3            -0.32             -0.32          0
## 4             2.94              2.94          0
## 5            -9.27             -9.27          0
## 6             0.77              0.77          0
## 7             1.31              1.31          0
## 8            -2.09             -2.09          0
## 9             1.43              1.43          0
## 10            0.52              0.52          0
## 11            0.52              0.52          0
## 12            1.38              1.38          0
## 13           -1.02             -1.02          0
## 14            2.89              2.89          0
## 15            1.59              1.59          0

literal 4

#verificar autovalores
descomposicion2 <-eigen (matriz_XX2)
autovalores2 <-descomposicion2$values
#visualizarlo
print(autovalores2)
## [1] 16976.7781334   709.9345923     0.2872743
#otra forma de verlo
print(autovalores2>0)
## [1] TRUE TRUE TRUE

#Ejercicio 3 Calcule las matrices A, P, M

load("C:/Users/MINEDUCYT/Downloads/modelo_estimado.RData")
#calcular X
Matriz_X3 <- model.matrix(modelo_estimado_1)
#calcular XX
matrix_xx3 <- t(Matriz_X3) %*% Matriz_X3
# Calcular A
matriz_a3 <- solve(matrix_xx3) %*% t(Matriz_X3)
# Calcular P
matriz_p3 <- Matriz_X3 %*% matriz_a3
#Calcular M
n3 <- diag(matriz_p3)
matriz_m3 <- diag(n3) - matriz_p3

Compruebe que los residuos en el objeto “modelo_estimado” son iguales al producto de M*y, donde “y” es la variable endógena en el modelo (“crime”

#residuos del modelo
residuos_modelo3 <- modelo_estimado_1$residuals
# residuos matriz.
datos_modelo3 <-modelo_estimado_1$model
residuos_matriz3 <- matriz_m3 %*% datos_modelo3$crime
#verificar
tabla <- cbind(residuos_modelo3, residuos_matriz3, residuos_modelo3-residuos_matriz3) |> as.data.frame() |>  round(digits = 2)

names(tabla) <- c("En modelo", "por matrices", "diferencia")

print(tabla)
##    En modelo por matrices diferencia
## 1    -311.71      -949.72     638.01
## 2     116.80      -638.65     755.46
## 3      45.25      -501.16     546.41
## 4     -34.45      -733.47     699.03
## 5     243.00      -797.72    1040.72
## 6    -145.12      -677.99     532.88
## 7      86.13      -346.37     432.50
## 8      88.31      -568.16     656.47
## 9     689.82      -457.91    1147.73
## 10   -163.29      -855.69     692.40
## 11     60.90      -184.58     245.48
## 12    126.92      -184.21     311.13
## 13    -19.27      -291.17     271.91
## 14    322.59      -617.47     940.07
## 15    -22.44      -499.88     477.44
## 16    128.18      -353.42     481.61
## 17    -70.82      -492.77     421.94
## 18   -227.95     -1118.51     890.56
## 19    287.10      -491.24     778.34
## 20    303.88      -633.52     937.40
## 21   -341.99      -463.97     121.99
## 22   -107.18      -873.02     765.83
## 23    -30.63      -347.85     317.22
## 24    189.45      -533.79     723.24
## 25   -811.14     -1190.15     379.02
## 26   -351.77      -525.67     173.90
## 27    102.71      -562.66     665.38
## 28    -23.36      -100.62      77.25
## 29     73.38      -252.10     325.47
## 30    -91.63      -223.52     131.89
## 31    324.03      -280.91     604.94
## 32   -115.85     -1002.26     886.40
## 33    113.65      -700.56     814.21
## 34    217.94      -825.60    1043.54
## 35   -112.70      -605.56     492.86
## 36     21.38      -570.84     592.23
## 37    -88.91      -578.01     489.10
## 38     99.42      -304.30     403.72
## 39   -102.65      -493.03     390.38
## 40    217.88      -765.70     983.59
## 41    -84.09      -283.19     199.09
## 42    137.78      -581.71     719.50
## 43     48.89      -690.51     739.40
## 44    -67.16      -358.29     291.13
## 45    -39.29      -396.59     357.31
## 46   -415.78      -525.17     109.38
## 47   -145.50      -645.33     499.83
## 48   -183.61      -441.31     257.71
## 49   -138.39      -309.29     170.90
## 50   -232.91      -512.91     280.00
## 51    434.17      -921.58    1355.75

Muestre que los autovalores de x’x son positivos (use el comando eigen)

descomposicion3 <-eigen(matrix_xx3)

autovalores3 <- descomposicion3$values
#visualizar
print(autovalores3)
## [1] 17956.580914   279.157317     1.681762
print(autovalores3>0)
## [1] TRUE TRUE TRUE

Ejercicio 4

Literal 1

library(readxl)
Investiment_Equation <- read_excel("C:/Users/MINEDUCYT/Downloads/Investiment_Equation.xlsx")

#estimar modelo
ecuacion_inversion <- lm(formula = InvReal ~ Trend + Inflation + PNBr + Interest, data = Investiment_Equation)
#norma apa
library(stargazer)
stargazer(ecuacion_inversion, title = "Ecuación de Inversión", type = "text")
## 
## Ecuación de Inversión
## ===============================================
##                         Dependent variable:    
##                     ---------------------------
##                               InvReal          
## -----------------------------------------------
## Trend                        -0.016***         
##                               (0.002)          
##                                                
## Inflation                     0.00002          
##                               (0.001)          
##                                                
## PNBr                         0.665***          
##                               (0.054)          
##                                                
## Interest                      -0.240*          
##                               (0.120)          
##                                                
## Constant                     -0.503***         
##                               (0.054)          
##                                                
## -----------------------------------------------
## Observations                    15             
## R2                             0.973           
## Adjusted R2                    0.962           
## Residual Std. Error       0.007 (df = 10)      
## F Statistic           90.089*** (df = 4; 10)   
## ===============================================
## Note:               *p<0.1; **p<0.05; ***p<0.01

Literal 2

#crear matrix X
model.matrix(ecuacion_inversion) -> Mat_X4

#Matriz M
n4 <- nrow(Mat_X4) 
Mat_M <- diag(n4)-Mat_X4%*%solve(t(Mat_X4)%*%Mat_X4)%*%t(Mat_X4)

#Residuos
Y4 <-Investiment_Equation$InvReal
Residuos4 <- Mat_M%*%Y4
print(Residuos4)
##             [,1]
## 1  -0.0100602233
## 2  -0.0009290882
## 3   0.0029656679
## 4   0.0078576839
## 5   0.0028109133
## 6   0.0006259732
## 7   0.0075909286
## 8  -0.0055352778
## 9  -0.0037254127
## 10  0.0006953129
## 11  0.0019904770
## 12 -0.0001288433
## 13 -0.0101976729
## 14  0.0068712384
## 15 -0.0008316770

literal 3

#Intervalo de confianza
confint(object = ecuacion_inversion, parm = "PNBr", level = .93)
##         3.5 %   96.5 %
## PNBr 0.554777 0.774317

Podemos concluir que el 93% de las estimaciones que hacemos el experimento se esperaria que el impacto de 1 un millón en el PNBr, se tradujece en un cambio esperado en un minimo de 0.55477 (millones) y un máximo 0.774317 (millones)

Ejercicio 5

Literal 1

load("C:/Users/MINEDUCYT/Downloads/consumption_equation.RData")

n5 <-nrow(P)
m5 <- diag(n5)-P
#residuos
residuos5 <- m5%*%C
print(residuos5)
##          [,1]
## 1   -5.859103
## 2    2.605057
## 3   45.765735
## 4   31.102448
## 5  -21.037889
## 6    7.008120
## 7   17.859663
## 8   10.705631
## 9   22.002328
## 10  -2.689665
## 11   7.784083
## 12 -13.127696
## 13  17.521565
## 14  17.304695
## 15 -16.308260
## 16  -5.255508
## 17   2.788211
## 18 -16.379339
## 19 -14.327554
## 20  11.749135
## 21 -31.424669
## 22 -23.329596
## 23  22.171806
## 24  -5.040038
## 25 -36.191398
## 26 -25.211753
## 27 -21.411271
## 28   1.410519
## 29 -24.229564
## 30  20.971808
## 31  43.342653
## 32  36.808458
## 33  17.882297
## 34 -33.100273
## 35 -37.819995
## 36 -49.370820
## 37  23.456143
## 38 -25.510341
## 39 -11.960629
## 40  -9.234201
## 41  21.949616
## 42   3.211123
## 43 -14.511436
## 44   3.197576
## 45 -62.396763
## 46 -66.854500
## 47   8.330745
## 48  91.963380
## 49  61.620735
## 50  48.148861
## 51 -10.717721
## 52 -84.069717
## 53 -56.426627
## 54 125.113605

Calcular de la varianza del error

#Numero de parametros (mirrar matriz XX)
K5 <- 4 
#varianza del error
var_error5=t(residuos5)%*%residuos5/(n5-K5)
print(var_error5)
##          [,1]
## [1,] 1428.746

Matriz de Var-Cov

#varianza covianza
#transformar la varianza del error a vector
var_error_5 <- as.vector(var_error5)
#Varainza por la inversa de XX
Var.cov5 <- var_error_5 * solve(XX)
print(Var.cov5)
##               (Intercept)             Yd               W             I
## (Intercept) 164.522304918 -0.09333539523  0.009670913575 10.5186890800
## Yd           -0.093335395  0.00018911268 -0.000032769561 -0.0072901023
## W             0.009670914 -0.00003276956  0.000006165749  0.0004193421
## I            10.518689080 -0.00729010228  0.000419342092  5.3203789879

Estimaciones del consumo

C_estimado<-P%*%C
plot(C_estimado)

#Comparar C estimado con su valor real, incluyendo residuos
cuadro <- as.data.frame(cbind(C,C_estimado,residuos5))

names(cuadro) <- c("C","estimado","Residuos")
print(cuadro)
##         C  estimado   Residuos
## 1   976.4  982.2591  -5.859103
## 2   998.1  995.4949   2.605057
## 3  1025.3  979.5343  45.765735
## 4  1090.9 1059.7976  31.102448
## 5  1107.1 1128.1379 -21.037889
## 6  1142.4 1135.3919   7.008120
## 7  1197.2 1179.3403  17.859663
## 8  1221.9 1211.1944  10.705631
## 9  1310.4 1288.3977  22.002328
## 10 1348.8 1351.4897  -2.689665
## 11 1381.8 1374.0159   7.784083
## 12 1393.0 1406.1277 -13.127696
## 13 1470.7 1453.1784  17.521565
## 14 1510.8 1493.4953  17.304695
## 15 1541.2 1557.5083 -16.308260
## 16 1617.3 1622.5555  -5.255508
## 17 1684.0 1681.2118   2.788211
## 18 1784.8 1801.1793 -16.379339
## 19 1897.6 1911.9276 -14.327554
## 20 2006.1 1994.3509  11.749135
## 21 2066.2 2097.6247 -31.424669
## 22 2184.2 2207.5296 -23.329596
## 23 2264.8 2242.6282  22.171806
## 24 2317.5 2322.5400  -5.040038
## 25 2405.2 2441.3914 -36.191398
## 26 2550.5 2575.7118 -25.211753
## 27 2675.9 2697.3113 -21.411271
## 28 2653.7 2652.2895   1.410519
## 29 2710.9 2735.1296 -24.229564
## 30 2868.9 2847.9282  20.971808
## 31 2992.1 2948.7573  43.342653
## 32 3124.7 3087.8915  36.808458
## 33 3203.2 3185.3177  17.882297
## 34 3193.0 3226.1003 -33.100273
## 35 3236.0 3273.8200 -37.819995
## 36 3275.5 3324.8708 -49.370820
## 37 3454.3 3430.8439  23.456143
## 38 3640.6 3666.1103 -25.510341
## 39 3820.9 3832.8606 -11.960629
## 40 3981.2 3990.4342  -9.234201
## 41 4113.4 4091.4504  21.949616
## 42 4279.5 4276.2889   3.211123
## 43 4393.7 4408.2114 -14.511436
## 44 4474.5 4471.3024   3.197576
## 45 4466.6 4528.9968 -62.396763
## 46 4594.5 4661.3545 -66.854500
## 47 4748.9 4740.5693   8.330745
## 48 4928.1 4836.1366  91.963380
## 49 5075.6 5013.9793  61.620735
## 50 5237.5 5189.3511  48.148861
## 51 5423.9 5434.6177 -10.717721
## 52 5683.7 5767.7697 -84.069717
## 53 5968.4 6024.8266 -56.426627
## 54 6257.8 6132.6864 125.113605

#Ejericio 6 Estima la ecuación de ventas, presenta sus resultados en formato APA.

load("C:/Users/MINEDUCYT/Downloads/datos_ventas (1).RData")

modelo_ventas2 <- lm(formula = ventas~tv+radio+periodico,data = datos_ventas)

stargazer(modelo_ventas2,title = "Modelo ventas",type = "text")
## 
## Modelo ventas
## ===============================================
##                         Dependent variable:    
##                     ---------------------------
##                               ventas           
## -----------------------------------------------
## tv                             0.045           
##                               (0.118)          
##                                                
## radio                        -3.450***         
##                               (0.206)          
##                                                
## periodico                    18.485***         
##                               (0.563)          
##                                                
## Constant                    -33.289***         
##                               (7.172)          
##                                                
## -----------------------------------------------
## Observations                    200            
## R2                             0.847           
## Adjusted R2                    0.844           
## Residual Std. Error      33.875 (df = 196)     
## F Statistic          360.758*** (df = 3; 196)  
## ===============================================
## Note:               *p<0.1; **p<0.05; ***p<0.01

Calcule los residuos a través de la matriz M

matriz_X6 <- model.matrix(modelo_ventas2)

#matriz M
n6 <- nrow(matriz_X6)
matriz_m6 <- diag(n6)-matriz_X6%*%solve(t(matriz_X6)%*%matriz_X6)%*%t(matriz_X6)

residuos_modelo6 <- modelo_ventas2$residuals

matriz_y <- datos_ventas$ventas
mresiduos_matrices <- residuos_modelo6%*%matriz_y

Calcule un intervalo de confianza del 96.8% para el impacto del gasto de publicidad en TV, en las ventas, e interprételo.

confint(object = modelo_ventas2, parm = "tv", level = .968)
##         1.6 %    98.4 %
## tv -0.2097376 0.2998052

Interpretación. podemos concluir que el 96.8% de las estimaciones que hacemos el experimento se esperaria que el impacto de una unidad en la TV, se tradujece en un cambio esperado en un minimo de -0.2097376 y un máximo 0.2998052