INSTAL PACKAGES YANG DIPERLUKAN

library(readxl)    #untuk impor .xlsx
library(car)       # untuk pengujian analisis
## Loading required package: carData
library(lmtest)    # untuk membuat model regresi
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric
data2 = read_xlsx("Data Potik.xlsx")
head(data2)
## # A tibble: 6 × 5
##   `Kabupaten/ Kota`   AHH   AKB   ABH   MCK
##   <chr>             <dbl> <dbl> <dbl> <dbl>
## 1 ACEH               69.9  19.4  1.58  76.5
## 2 SUMATERA UTARA     69.1  18.3  0.77  87.3
## 3 SUMATERA BARAT     69.5  16.4  0.77  76.2
## 4 RIAU               71.6  15.7  0.71  91.8
## 5 JAMBI              71.2  17.0  1.64  85.0
## 6 SUMATERA SELATAN   69.9  16.8  1.16  82.5

#ANALISIS STATISTIK DESKRIPTIF

summary(data2)
##  Kabupaten/ Kota         AHH             AKB             ABH         
##  Length:34          Min.   :65.06   Min.   :10.38   Min.   : 0.2600  
##  Class :character   1st Qu.:68.67   1st Qu.:15.55   1st Qu.: 0.9875  
##  Mode  :character   Median :69.96   Median :17.23   Median : 1.7050  
##                     Mean   :70.04   Mean   :19.74   Mean   : 3.3024  
##                     3rd Qu.:71.53   3rd Qu.:24.30   3rd Qu.: 4.6750  
##                     Max.   :74.99   Max.   :38.17   Max.   :20.3500  
##       MCK       
##  Min.   :61.74  
##  1st Qu.:76.27  
##  Median :82.33  
##  Mean   :80.92  
##  3rd Qu.:85.49  
##  Max.   :93.55

#ANALISIS STATISTIK INFERENSIA

x1 <- data2$AKB                   # mendefinisikan data AKB sebagai variabel x1
x2 <- data2$ABH                    # mendefinisikan data ABH sebagai variabel x2
x3 <- data2$MCK                  # mendefinisikan data MCK sebagai variabel x3
y <- data2$AHH                  # mendefinisikan data Y sebagai variabel y

1.Pembentukan model dan pendugaan parameter model

model<- lm(y ~ x1+x2+x3)
model$coefficients 
## (Intercept)          x1          x2          x3 
## 73.50365681 -0.27919661  0.03234640  0.02398661

2. Pengujian keberartian model

summary(model)
## 
## Call:
## lm(formula = y ~ x1 + x2 + x3)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -2.24410 -0.94660 -0.06875  1.10792  2.88728 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 73.50366    4.83556  15.201 1.23e-15 ***
## x1          -0.27920    0.05565  -5.017 2.22e-05 ***
## x2           0.03235    0.07309   0.443    0.661    
## x3           0.02399    0.04878   0.492    0.627    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1.478 on 30 degrees of freedom
## Multiple R-squared:  0.688,  Adjusted R-squared:  0.6568 
## F-statistic: 22.05 on 3 and 30 DF,  p-value: 9.75e-08

UJI HIPOTESIS DENGAN F-STATISTICS (UJI SIMULTAN) UJI HIPOTESIS KOEFISIEN REGRESI DENGAN T-STATISTICS (UJI PARSIAL)

3. Penilaian ketepatan model

summary(model)
## 
## Call:
## lm(formula = y ~ x1 + x2 + x3)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -2.24410 -0.94660 -0.06875  1.10792  2.88728 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 73.50366    4.83556  15.201 1.23e-15 ***
## x1          -0.27920    0.05565  -5.017 2.22e-05 ***
## x2           0.03235    0.07309   0.443    0.661    
## x3           0.02399    0.04878   0.492    0.627    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1.478 on 30 degrees of freedom
## Multiple R-squared:  0.688,  Adjusted R-squared:  0.6568 
## F-statistic: 22.05 on 3 and 30 DF,  p-value: 9.75e-08

4. Pemeriksaana asumsi

  1. ASUMSI NORMAL
res <- model$residuals                                    # mendefinisikan residual 
ks.test(res, "pnorm", mean=mean(res),sd=sd(res))        # Uji Kolmogorov-Smirnov --uji kenormalan
## 
##  Exact one-sample Kolmogorov-Smirnov test
## 
## data:  res
## D = 0.079896, p-value = 0.9696
## alternative hypothesis: two-sided
  1. PENGUJIAN ASUMSI HOMOSKEDASTISITAS
# BENTUK VARIABEL NILAI ABSOLUT DARI RESIDUAL 
abs_res <- abs(res)

# REGRESIKAN SELURUH VARIABEL BEBAS TERHADAP NILAI ABSOLUT DARI RESIDUAL
model_glejser <- lm(abs_res~x1+x2+x3)
summary(model_glejser)
## 
## Call:
## lm(formula = abs_res ~ x1 + x2 + x3)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -1.0862 -0.5511 -0.0331  0.5326  1.6869 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)
## (Intercept) 0.534740   2.640061   0.203    0.841
## x1          0.004533   0.030381   0.149    0.882
## x2          0.008996   0.039904   0.225    0.823
## x3          0.006287   0.026634   0.236    0.815
## 
## Residual standard error: 0.8071 on 30 degrees of freedom
## Multiple R-squared:  0.003005,   Adjusted R-squared:  -0.09669 
## F-statistic: 0.03014 on 3 and 30 DF,  p-value: 0.9928
  1. PEMERIKSAAN ASUMSI NONMULTIKOLINIERITAS
round(cor(data2[,c(3,4,5)]),2)  # menampilkan tabel korelasi antarvariabel
##       AKB   ABH   MCK
## AKB  1.00  0.39 -0.76
## ABH  0.39  1.00 -0.42
## MCK -0.76 -0.42  1.00
vif(model)
##       x1       x2       x3 
## 2.369611 1.238668 2.443183