#Se importa la base a ser analizada:

Conjunto de datos #1:

data=read.csv(url("https://raw.githubusercontent.com/geovannychoez/prueba/master/MTCars.csv"), header = TRUE)
View(data)

Se detectan 205 observaciones y 26 variables.

names(data)
##  [1] "car_ID"           "symboling"        "CarName"          "fueltype"        
##  [5] "aspiration"       "doornumber"       "carbody"          "drivewheel"      
##  [9] "enginelocation"   "wheelbase"        "carlength"        "carwidth"        
## [13] "carheight"        "curbweight"       "enginetype"       "cylindernumber"  
## [17] "enginesize"       "fuelsystem"       "boreratio"        "stroke"          
## [21] "compressionratio" "horsepower"       "peakrpm"          "citympg"         
## [25] "highwaympg"       "price"
str(data)
## 'data.frame':    205 obs. of  26 variables:
##  $ car_ID          : int  1 2 3 4 5 6 7 8 9 10 ...
##  $ symboling       : int  3 3 1 2 2 2 1 1 1 0 ...
##  $ CarName         : chr  "alfa-romero giulia" "alfa-romero stelvio" "alfa-romero Quadrifoglio" "audi 100 ls" ...
##  $ fueltype        : chr  "gas" "gas" "gas" "gas" ...
##  $ aspiration      : chr  "std" "std" "std" "std" ...
##  $ doornumber      : chr  "two" "two" "two" "four" ...
##  $ carbody         : chr  "convertible" "convertible" "hatchback" "sedan" ...
##  $ drivewheel      : chr  "rwd" "rwd" "rwd" "fwd" ...
##  $ enginelocation  : chr  "front" "front" "front" "front" ...
##  $ wheelbase       : num  88.6 88.6 94.5 99.8 99.4 ...
##  $ carlength       : num  169 169 171 177 177 ...
##  $ carwidth        : num  64.1 64.1 65.5 66.2 66.4 66.3 71.4 71.4 71.4 67.9 ...
##  $ carheight       : num  48.8 48.8 52.4 54.3 54.3 53.1 55.7 55.7 55.9 52 ...
##  $ curbweight      : int  2548 2548 2823 2337 2824 2507 2844 2954 3086 3053 ...
##  $ enginetype      : chr  "dohc" "dohc" "ohcv" "ohc" ...
##  $ cylindernumber  : chr  "four" "four" "six" "four" ...
##  $ enginesize      : int  130 130 152 109 136 136 136 136 131 131 ...
##  $ fuelsystem      : chr  "mpfi" "mpfi" "mpfi" "mpfi" ...
##  $ boreratio       : num  3.47 3.47 2.68 3.19 3.19 3.19 3.19 3.19 3.13 3.13 ...
##  $ stroke          : num  2.68 2.68 3.47 3.4 3.4 3.4 3.4 3.4 3.4 3.4 ...
##  $ compressionratio: num  9 9 9 10 8 8.5 8.5 8.5 8.3 7 ...
##  $ horsepower      : int  111 111 154 102 115 110 110 110 140 160 ...
##  $ peakrpm         : int  5000 5000 5000 5500 5500 5500 5500 5500 5500 5500 ...
##  $ citympg         : int  21 21 19 24 18 19 19 19 17 16 ...
##  $ highwaympg      : int  27 27 26 30 22 25 25 25 20 22 ...
##  $ price           : num  13495 16500 16500 13950 17450 ...

#De las 26 variables 10 no son numéricas, por tanto no se las considera para la matriz de correlacion

Conjunto de datos #2:

data2=read.csv(url("https://raw.githubusercontent.com/geovannychoez/prueba/master/UsedCars.csv"), header = TRUE)
View(data2)

Se detectan 1874 observaciones y 20 variables.

names(data2)
##  [1] "Make"               "Model"              "Price"             
##  [4] "Year"               "Kilometer"          "Fuel.Type"         
##  [7] "Transmission"       "Location"           "Color"             
## [10] "Owner"              "Seller.Type"        "Engine"            
## [13] "Max.Power"          "Max.Torque"         "Drivetrain"        
## [16] "Length"             "Width"              "Height"            
## [19] "Seating.Capacity"   "Fuel.Tank.Capacity"
str(data2)
## 'data.frame':    1874 obs. of  20 variables:
##  $ Make              : chr  "Honda" "Maruti Suzuki" "Hyundai" "Toyota" ...
##  $ Model             : chr  "Amaze 1.2 VX i-VTEC" "Swift DZire VDI" "i10 Magna 1.2 Kappa2" "Glanza G" ...
##  $ Price             : int  505000 450000 220000 799000 1950000 675000 2650000 1390000 575000 591000 ...
##  $ Year              : int  2017 2014 2011 2019 2018 2017 2017 2017 2015 2017 ...
##  $ Kilometer         : int  87150 75000 67000 37500 69000 73315 75000 56000 85000 20281 ...
##  $ Fuel.Type         : chr  "Petrol" "Diesel" "Petrol" "Petrol" ...
##  $ Transmission      : chr  "Manual" "Manual" "Manual" "Manual" ...
##  $ Location          : chr  "Pune" "Ludhiana" "Lucknow" "Mangalore" ...
##  $ Color             : chr  "Grey" "White" "Maroon" "Red" ...
##  $ Owner             : chr  "First" "Second" "First" "First" ...
##  $ Seller.Type       : chr  "Corporate" "Individual" "Individual" "Individual" ...
##  $ Engine            : chr  "1198 cc" "1248 cc" "1197 cc" "1197 cc" ...
##  $ Max.Power         : chr  "87 bhp @ 6000 rpm" "74 bhp @ 4000 rpm" "79 bhp @ 6000 rpm" "82 bhp @ 6000 rpm" ...
##  $ Max.Torque        : chr  "109 Nm @ 4500 rpm" "190 Nm @ 2000 rpm" "112.7619 Nm @ 4000 rpm" "113 Nm @ 4200 rpm" ...
##  $ Drivetrain        : chr  "FWD" "FWD" "FWD" "FWD" ...
##  $ Length            : int  3990 3995 3585 3995 4735 4490 4439 4670 4331 3985 ...
##  $ Width             : int  1680 1695 1595 1745 1830 1730 1821 1814 1822 1734 ...
##  $ Height            : int  1505 1555 1550 1510 1795 1485 1612 1476 1671 1505 ...
##  $ Seating.Capacity  : int  5 5 5 5 7 5 5 5 5 5 ...
##  $ Fuel.Tank.Capacity: num  35 42 35 37 55 43 51 50 50 45 ...

#De las 20 variables 12 no son numéricas, por tanto no se las considera para la matriz de correlacion

#Se importan librerias para graficas

knitr::opts_chunk$set(echo = TRUE)
library(highcharter)
## Registered S3 method overwritten by 'quantmod':
##   method            from
##   as.zoo.data.frame zoo
if (!requireNamespace("corrplot", quietly = TRUE)) {
  install.packages("corrplot")
}
library(corrplot)
## corrplot 0.92 loaded

Se crea “variables_numericas_data”, matriz que contiene las 16 variables numericas, de Data.

#La razón se debe a que este dataframe excluye variables no numéricas para poder graficar matriz de correlacion, fundamental para empezar el modelo de regresion.

variables_numericas_data= data[,c(1:2,10:14,17,19:26)]
View(variables_numericas_data)
names(variables_numericas_data)
##  [1] "car_ID"           "symboling"        "wheelbase"        "carlength"       
##  [5] "carwidth"         "carheight"        "curbweight"       "enginesize"      
##  [9] "boreratio"        "stroke"           "compressionratio" "horsepower"      
## [13] "peakrpm"          "citympg"          "highwaympg"       "price"
matriz_corr_data <- cor(variables_numericas_data)
matriz_corr_data
##                       car_ID    symboling  wheelbase  carlength    carwidth
## car_ID            1.00000000 -0.151621137  0.1297288  0.1706364  0.05238661
## symboling        -0.15162114  1.000000000 -0.5319537 -0.3576115 -0.23291906
## wheelbase         0.12972878 -0.531953682  1.0000000  0.8745875  0.79514364
## carlength         0.17063639 -0.357611523  0.8745875  1.0000000  0.84111827
## carwidth          0.05238661 -0.232919061  0.7951436  0.8411183  1.00000000
## carheight         0.25596004 -0.541038200  0.5894348  0.4910295  0.27921032
## curbweight        0.07196156 -0.227690588  0.7763863  0.8777285  0.86703246
## enginesize       -0.03392984 -0.105789709  0.5693287  0.6833599  0.73543340
## boreratio         0.26006368 -0.130051360  0.4887499  0.6064544  0.55914991
## stroke           -0.16082362 -0.008735141  0.1609590  0.1295326  0.18294169
## compressionratio  0.15027591 -0.178515084  0.2497858  0.1584137  0.18112863
## horsepower       -0.01500557  0.070872724  0.3532945  0.5526230  0.64073208
## peakrpm          -0.20378920  0.273606245 -0.3604687 -0.2872422 -0.22001230
## citympg           0.01594004 -0.035822628 -0.4704136 -0.6709087 -0.64270434
## highwaympg        0.01125532  0.034606001 -0.5440819 -0.7046616 -0.67721792
## price            -0.10909334 -0.079978225  0.5778156  0.6829200  0.75932530
##                    carheight  curbweight  enginesize    boreratio       stroke
## car_ID            0.25596004  0.07196156 -0.03392984  0.260063680 -0.160823619
## symboling        -0.54103820 -0.22769059 -0.10578971 -0.130051360 -0.008735141
## wheelbase         0.58943476  0.77638633  0.56932868  0.488749875  0.160959047
## carlength         0.49102946  0.87772846  0.68335987  0.606454358  0.129532611
## carwidth          0.27921032  0.86703246  0.73543340  0.559149909  0.182941693
## carheight         1.00000000  0.29557173  0.06714874  0.171070922 -0.055306674
## curbweight        0.29557173  1.00000000  0.85059407  0.648479749  0.168790035
## enginesize        0.06714874  0.85059407  1.00000000  0.583774327  0.203128588
## boreratio         0.17107092  0.64847975  0.58377433  1.000000000 -0.055908983
## stroke           -0.05530667  0.16879004  0.20312859 -0.055908983  1.000000000
## compressionratio  0.26121423  0.15136174  0.02897136  0.005197339  0.186110110
## horsepower       -0.10880206  0.75073925  0.80976865  0.573676823  0.080939536
## peakrpm          -0.32041072 -0.26624318 -0.24465983 -0.254975528 -0.067963753
## citympg          -0.04863963 -0.75741378 -0.65365792 -0.584531716 -0.042144754
## highwaympg       -0.10735763 -0.79746479 -0.67746991 -0.587011784 -0.043930930
## price             0.11933623  0.83530488  0.87414480  0.553173237  0.079443084
##                  compressionratio  horsepower     peakrpm     citympg
## car_ID                0.150275906 -0.01500557 -0.20378920  0.01594004
## symboling            -0.178515084  0.07087272  0.27360625 -0.03582263
## wheelbase             0.249785845  0.35329448 -0.36046875 -0.47041361
## carlength             0.158413706  0.55262297 -0.28724220 -0.67090866
## carwidth              0.181128627  0.64073208 -0.22001230 -0.64270434
## carheight             0.261214226 -0.10880206 -0.32041072 -0.04863963
## curbweight            0.151361740  0.75073925 -0.26624318 -0.75741378
## enginesize            0.028971360  0.80976865 -0.24465983 -0.65365792
## boreratio             0.005197339  0.57367682 -0.25497553 -0.58453172
## stroke                0.186110110  0.08093954 -0.06796375 -0.04214475
## compressionratio      1.000000000 -0.20432623 -0.43574051  0.32470142
## horsepower           -0.204326226  1.00000000  0.13107251 -0.80145618
## peakrpm              -0.435740514  0.13107251  1.00000000 -0.11354438
## citympg               0.324701425 -0.80145618 -0.11354438  1.00000000
## highwaympg            0.265201389 -0.77054389 -0.05427481  0.97133704
## price                 0.067983506  0.80813882 -0.08526715 -0.68575134
##                   highwaympg       price
## car_ID            0.01125532 -0.10909334
## symboling         0.03460600 -0.07997822
## wheelbase        -0.54408192  0.57781560
## carlength        -0.70466160  0.68292002
## carwidth         -0.67721792  0.75932530
## carheight        -0.10735763  0.11933623
## curbweight       -0.79746479  0.83530488
## enginesize       -0.67746991  0.87414480
## boreratio        -0.58701178  0.55317324
## stroke           -0.04393093  0.07944308
## compressionratio  0.26520139  0.06798351
## horsepower       -0.77054389  0.80813882
## peakrpm          -0.05427481 -0.08526715
## citympg           0.97133704 -0.68575134
## highwaympg        1.00000000 -0.69759909
## price            -0.69759909  1.00000000

Se crea “variables_numericas_data2”, matriz que contiene las 12 variables numericas, de Data2.

#La razón se debe a que este dataframe excluye variables no numéricas para poder graficar matriz de correlacion, fundamental para empezar el modelo de regresion.

variables_numericas_data2= data2[,c(3:5,16:20)]
View(variables_numericas_data2)
names(variables_numericas_data2)
## [1] "Price"              "Year"               "Kilometer"         
## [4] "Length"             "Width"              "Height"            
## [7] "Seating.Capacity"   "Fuel.Tank.Capacity"
matriz_corr_data2 <- cor(variables_numericas_data2)
matriz_corr_data2
##                          Price          Year    Kilometer     Length
## Price               1.00000000  0.3093808616 -0.147276151 0.56887490
## Year                0.30938086  1.0000000000 -0.291739924 0.08517813
## Kilometer          -0.14727615 -0.2917399243  1.000000000 0.03781718
## Length              0.56887490  0.0851781331  0.037817177 1.00000000
## Width               0.57709978  0.1822201159  0.008479363 0.79722805
## Height              0.09296771  0.1268485819  0.085727621 0.19470421
## Seating.Capacity   -0.02487942 -0.0001130477  0.111102936 0.29852678
## Fuel.Tank.Capacity  0.58610949  0.0448594975  0.052446915 0.80981209
##                          Width     Height Seating.Capacity Fuel.Tank.Capacity
## Price              0.577099782 0.09296771    -0.0248794220         0.58610949
## Year               0.182220116 0.12684858    -0.0001130477         0.04485950
## Kilometer          0.008479363 0.08572762     0.1111029359         0.05244692
## Length             0.797228050 0.19470421     0.2985267764         0.80981209
## Width              1.000000000 0.32692755     0.2290563388         0.79131609
## Height             0.326927546 1.00000000     0.6953727610         0.40871653
## Seating.Capacity   0.229056339 0.69537276     1.0000000000         0.31392753
## Fuel.Tank.Capacity 0.791316085 0.40871653     0.3139275291         1.00000000

Gràfica matriz de correlacion: Data (variables numèricas)

corrplot(matriz_corr_data, 
         method = "color", 
         type = "upper", 
         tl.col = "black", 
         tl.srt = 45,      # Rotación de los nombres
         tl.cex = 0.8,     # Tamaño del texto de las etiquetas
         title = "Matriz de Correlación: Data",
         addCoef.col = "black",
         number.cex = 0.7) # Tamaño del texto de los coeficientes

#Variable “Price”, se relaciona positivamente de manera significativa (>0.5) con 7 variables y negativamente de manera significativa (<-0.5) con 2 variables

Se selecciona variable “Price” como “y” del modelo por ser la que mayor relación guarda con las demas variables:

#wheelbase, carlength, carwidth, curbweigh, enginesize, boreratio, horsepower,citympg, highwaympg

Gràfica matriz de correlacion: Data2 (variables numèricas)

corrplot(matriz_corr_data2, 
         method = "color", 
         type = "upper", 
         tl.col = "black", 
         tl.srt = 45,      # Rotación de los nombres
         tl.cex = 0.8,     # Tamaño del texto de las etiquetas
         title = "Matriz de Correlación: Data2",
         addCoef.col = "black",
         number.cex = 0.7) # Tamaño del texto de los coeficientes

#Variable “Price”, se relaciona positivamente de manera significativa (>0.5) con 3 variables

Se selecciona variable “Price” como “y” del modelo por ser la que mayor relación guarda con las demas variables:

#Length, Width, Fuel.Tank.Capacity

#Para facilitar la escritura se renombra matriz

n_data <- variables_numericas_data
n_data2 <- variables_numericas_data2
View(n_data)

MODELO REGRESION LINEAL MULTIPLE: DATA

modelo_lineal_Data <- lm(
  n_data$price ~ n_data$wheelbase+n_data$carlength+n_data$carwidth+n_data$curbweigh+n_data$enginesize+n_data$boreratio+n_data$horsepower+n_data$citympg+n_data$highwaympg)
modelo_lineal_Data
## 
## Call:
## lm(formula = n_data$price ~ n_data$wheelbase + n_data$carlength + 
##     n_data$carwidth + n_data$curbweigh + n_data$enginesize + 
##     n_data$boreratio + n_data$horsepower + n_data$citympg + n_data$highwaympg)
## 
## Coefficients:
##       (Intercept)   n_data$wheelbase   n_data$carlength    n_data$carwidth  
##        -43223.926            109.895            -57.853            532.467  
##  n_data$curbweigh  n_data$enginesize   n_data$boreratio  n_data$horsepower  
##             2.918             83.615          -1140.464             53.754  
##    n_data$citympg  n_data$highwaympg  
##          -119.815            122.855

#Se obtiene: Y=B0+B1(n_data\(wheelbase)+B2(n_data\)carlength)+B3(n_data\(carwidth)+B4(n_data\)curbweigh)+B5(n_data\(enginesize)+B6(n_data\)boreratio)+B7(n_data\(horsepower)+B8(n_data\)citympg)+B9(n_data$highwaympg)

#B0= -43223.926 | B1= 109.895 | B2= -57.853 | B3= 532.467 | B4= 2.918 | B5= 83.615 | B6= -1140.464 | B7= 53.754 | B8= -119.815 | B9= 122.855

MODELO REGRESION LINEAL MULTIPLE: DATA2

modelo_lineal_Data2 <- lm(
  n_data2$Price ~ n_data2$Length+n_data2$Width+n_data2$Fuel.Tank.Capacity)
modelo_lineal_Data2
## 
## Call:
## lm(formula = n_data2$Price ~ n_data2$Length + n_data2$Width + 
##     n_data2$Fuel.Tank.Capacity)
## 
## Coefficients:
##                (Intercept)              n_data2$Length  
##                 -1.210e+07                   9.343e+02  
##              n_data2$Width  n_data2$Fuel.Tank.Capacity  
##                  4.300e+03                   4.252e+04

#Se obtiene: Y=B0+B1(n_data2\(Length+B2(n_data2\)Width)+B3(n_data2$Fuel.Tank.Capacity)

#B0= -1.210e+07 | B1= 9.343e+02 | B2= 4.300e+03 | B3= 4.252e+04

INFERENCIA SOBRE LOS COEFICIENTE: DATA

summary(modelo_lineal_Data)
## 
## Call:
## lm(formula = n_data$price ~ n_data$wheelbase + n_data$carlength + 
##     n_data$carwidth + n_data$curbweigh + n_data$enginesize + 
##     n_data$boreratio + n_data$horsepower + n_data$citympg + n_data$highwaympg)
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
##  -8297  -1542     31   1307  14444 
## 
## Coefficients:
##                     Estimate Std. Error t value Pr(>|t|)    
## (Intercept)       -43223.926  13760.207  -3.141 0.001944 ** 
## n_data$wheelbase     109.895    101.743   1.080 0.281418    
## n_data$carlength     -57.853     57.933  -0.999 0.319217    
## n_data$carwidth      532.467    255.561   2.084 0.038508 *  
## n_data$curbweigh       2.918      1.651   1.767 0.078749 .  
## n_data$enginesize     83.615     13.434   6.224 2.91e-09 ***
## n_data$boreratio   -1140.464   1212.508  -0.941 0.348083    
## n_data$horsepower     53.754     15.447   3.480 0.000619 ***
## n_data$citympg      -119.815    185.536  -0.646 0.519183    
## n_data$highwaympg    122.855    170.820   0.719 0.472872    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 3444 on 195 degrees of freedom
## Multiple R-squared:  0.8223, Adjusted R-squared:  0.8141 
## F-statistic: 100.3 on 9 and 195 DF,  p-value: < 2.2e-16

PRUEBA F DE SIGNIFICANCIA GLOBAL |

#Con p-value: < 2.2e-16 menor a 0.05, RECHAZO H0: (b1=b2…=bp=0)

PRUEBA T-STUDENT DE SIGNIFICANCIA INDIVIDUAL |

#Si Pr(>|t|) es menor a significancia, RECHAZO H0: bi=0

#0.001944 es menor 0.025 (el intercepto no afecta a los estimadores del modelo)

#0.281418 es mayor 0.025 NO RECHAZO H0

#0.319217 es mayor 0.025 NO RECHAZO H0

#0.038508 es mayor 0.025 NO RECHAZO H0

#0.078749 es mayor 0.025 NO RECHAZO H0

#2.91e-09 es menor 0.025 RECHAZO H0

#0.348083 es mayor 0.025 NO RECHAZO H0

#0.000619 es menor 0.025 RECHAZO H0

#0.519183 es mayor 0.025 NO RECHAZO H0

#0.472872 es mayor 0.025 NO RECHAZO H0

#LOS DATOS SE AJUSTAN Adjusted R-squared: 0.8141 AL MODELO, POR TANTO EL MODELO ES LO SUFICIENTEMENTE FIABLE PARA LAS PREVISIONES FUTURAS

CONCLUSION DEL MODELO

#El modelo de muestra de regresion lineal mùltiple indica que las variables seleccionadas, explican a “Y” y sì logran predecirla

MODELO REGRESION LINEAL MULTIPLE: DATA (SEGUNDO INTENTO)

modelo_lineal_Data_intento2 <- lm(
  n_data$price ~ n_data$enginesize+n_data$horsepower)
modelo_lineal_Data_intento2
## 
## Call:
## lm(formula = n_data$price ~ n_data$enginesize + n_data$horsepower)
## 
## Coefficients:
##       (Intercept)  n_data$enginesize  n_data$horsepower  
##          -8389.73             122.45              58.85
summary(modelo_lineal_Data_intento2)
## 
## Call:
## lm(formula = n_data$price ~ n_data$enginesize + n_data$horsepower)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -10946.0  -1946.7   -218.8   1775.5  13403.1 
## 
## Coefficients:
##                   Estimate Std. Error t value Pr(>|t|)    
## (Intercept)       -8389.73     822.53 -10.200  < 2e-16 ***
## n_data$enginesize   122.45      10.46  11.709  < 2e-16 ***
## n_data$horsepower    58.85      11.01   5.344 2.45e-07 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 3650 on 202 degrees of freedom
## Multiple R-squared:  0.7933, Adjusted R-squared:  0.7913 
## F-statistic: 387.7 on 2 and 202 DF,  p-value: < 2.2e-16

#En este segundo intento nos quedamos con las variables “enginesize” y “horsepower” que explican y predicen significativamente a “price”

PRUEBA F DE SIGNIFICANCIA GLOBAL |

#Con p-value: < 2.2e-16 menor a 0.05, RECHAZO H0: (b1=b2…=bp=0)

PRUEBA T-STUDENT DE SIGNIFICANCIA INDIVIDUAL |

#Si Pr(>|t|) es menor a significancia, RECHAZO H0: bi=0

#2e-16 es menor 0.025 (el intercepto no afecta a los estimadores del modelo)

#< 2e-16 es menor 0.025 RECHAZO H0

#2.45e-07 es menor 0.025 RECHAZO H0

#LOS DATOS SE AJUSTAN Adjusted R-squared: 0.7913 AL MODELO, POR TANTO EL MODELO ES FIABLE PARA LAS PREVISIONES FUTURAS, MÀS NO COMO EN EL PRIMER INTENTO

CONCLUSION DEL MODELO

#El modelo de muestra de regresion lineal mùltiple indica que las variables seleccionadas, explican a “Y” y sì logran predecirla, aunque con menos exactitud que el primer modelo

INFERENCIA SOBRE LOS COEFICIENTE: DATA2

summary(modelo_lineal_Data2)
## 
## Call:
## lm(formula = n_data2$Price ~ n_data2$Length + n_data2$Width + 
##     n_data2$Fuel.Tank.Capacity)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -4226517  -778163  -216094   412501 31125964 
## 
## Coefficients:
##                              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                -1.210e+07  8.158e+05 -14.838  < 2e-16 ***
## n_data2$Length              9.343e+02  1.909e+02   4.894 1.07e-06 ***
## n_data2$Width               4.300e+03  6.084e+02   7.068 2.22e-12 ***
## n_data2$Fuel.Tank.Capacity  4.252e+04  5.421e+03   7.844 7.30e-15 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1903000 on 1870 degrees of freedom
## Multiple R-squared:  0.3857, Adjusted R-squared:  0.3847 
## F-statistic: 391.4 on 3 and 1870 DF,  p-value: < 2.2e-16

PRUEBA F DE SIGNIFICANCIA GLOBAL |

#Con p-value: < 2.2e-16 menor a 0.05, RECHAZO H0: (b1=b2…=bp=0)

PRUEBA T-STUDENT DE SIGNIFICANCIA INDIVIDUAL |

#Si Pr(>|t|) es menor a significancia, RECHAZO H0: bi=0

#2e-16 es menor 0.025 (el intercepto no afecta a los estimadores del modelo)

#1.07e-06 es menor 0.025 RECHAZO H0

#2.22e-12 es menor 0.025 RECHAZO H0

#7.30e-15 es menor 0.025 RECHAZO H0

#LOS DATOS SE AJUSTAN Adjusted R-squared: 0.3847 AL MODELO, POR TANTO EL MODELO NO ES LO SUFICIENTEMENTE FIABLE PARA LAS PREVISIONES FUTURAS

CONCLUSION DEL MODELO

#El modelo de muestra de regresion lineal mùltiple indica que las variables seleccionadas, explican a “Y” y no logran predecirla