library(readxl)
library(ggplot2)
library(car)
## Loading required package: carData
library(lmtest)
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric
# Dataset 1
data1 <- read_excel("Dataset 1 dan 2 Regnon.xlsx",
                    sheet = "Dataset 1")
data1
## # A tibble: 9 × 4
##       Y    X1    X2    X3
##   <dbl> <dbl> <dbl> <dbl>
## 1  57.5    78  2.75  29.5
## 2  52.8    69  2.15  26.3
## 3  61.3    77  4.41  32.2
## 4  67      88  5.52  36.5
## 5  53.5    67  3.21  27.2
## 6  62.7    80  4.32  27.7
## 7  56.2    74  2.31  28.3
## 8  68.5    94  4.3   30.3
## 9  69.2   102  3.71  28.7
## Scatter Plot Umur terhadap Pancang Bayi
ggplot(data1, aes(x = X1, y = Y)) +
  geom_point(size = 3) +
  geom_smooth(method = "lm", se = FALSE) +
  labs(
    title = "Scatter Plot Umur terhadap Panjang bayi - Dataset 1",
    x = "Umur",
    y = "Panjang bayi"
  ) +
  theme_minimal()
## `geom_smooth()` using formula = 'y ~ x'

## Scatter Plot Berat Badan terhadap Panjang Bayi
ggplot(data1, aes(x = X2, y = Y)) +
  geom_point(size = 3) +
  geom_smooth(method = "lm", se = FALSE) +
  labs(
    title = "Scatter Plot Berat Badan terhadap Panjang Bayi - Dataset 1",
    x = "Berat Badan",
    y = "Panjang Bayi"
  ) +
  theme_minimal()
## `geom_smooth()` using formula = 'y ~ x'

## Scatter Plot Lingkar Dada terhadap Panjang Bayi
ggplot(data1, aes(x = X3, y = Y)) +
  geom_point(size = 3) +
  geom_smooth(method = "lm", se = FALSE) +
  labs(
    title = "Scatter Plot Lingkar Dada terhadap Panjang Bayi - Dataset 1",
    x = "Lingkar Dada",
    y = "Panjang Bayi"
  ) +
  theme_minimal()
## `geom_smooth()` using formula = 'y ~ x'

# RLB Dataset 1

m4=lm(Y~X1+X2+X3,data=data1)
summary(m4)
## 
## Call:
## lm(formula = Y ~ X1 + X2 + X3, data = data1)
## 
## Residuals:
##       1       2       3       4       5       6       7       8       9 
## -0.2981 -0.2142  0.4714 -0.4746 -0.9524  0.4761  0.9274  0.7466 -0.6823 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 21.87353    4.07389   5.369  0.00302 ** 
## X1           0.41277    0.03067  13.460 4.05e-05 ***
## X2           2.20267    0.47199   4.667  0.00550 ** 
## X3          -0.07895    0.15551  -0.508  0.63330    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.8484 on 5 degrees of freedom
## Multiple R-squared:  0.9888, Adjusted R-squared:  0.9821 
## F-statistic: 147.1 on 3 and 5 DF,  p-value: 2.696e-05
#Pendeteksian Multikolinieritas
vif(m4)
##       X1       X2       X3 
## 1.403219 3.093549 2.607991
# Pengujian Asumsi Model 4
# Uji Non-Heteroskedastisitas
# Breusch-Pagan Test
bptest(m4)
## 
##  studentized Breusch-Pagan test
## 
## data:  m4
## BP = 0.52402, df = 3, p-value = 0.9136
# Glejser Test
e4=resid(m4)
ae4=abs(e4)
ae4
##         1         2         3         4         5         6         7         8 
## 0.2980857 0.2141744 0.4714083 0.4745650 0.9524106 0.4760829 0.9274363 0.7466056 
##         9 
## 0.6822975
aer4=lm(ae4~X1+X2+X3,data=data1)
summary(aer4)
## 
## Call:
## lm(formula = ae4 ~ X1 + X2 + X3, data = data1)
## 
## Residuals:
##        1        2        3        4        5        6        7        8 
## -0.24968 -0.37078 -0.06495 -0.01987  0.35744 -0.17650  0.37477  0.12608 
##        9 
##  0.02347 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)
## (Intercept)  1.000238   1.548904   0.646    0.547
## X1           0.002391   0.011660   0.205    0.846
## X2           0.035130   0.179452   0.196    0.853
## X3          -0.024936   0.059127  -0.422    0.691
## 
## Residual standard error: 0.3226 on 5 degrees of freedom
## Multiple R-squared:  0.04467,    Adjusted R-squared:  -0.5285 
## F-statistic: 0.07793 on 3 and 5 DF,  p-value: 0.9692
# Uji Non-Autokorelasi
# Durbin-Watson Test
dwtest(m4, alternative='two.sided')
## 
##  Durbin-Watson test
## 
## data:  m4
## DW = 1.6446, p-value = 0.233
## alternative hypothesis: true autocorrelation is not 0
# Breusch-Godfrey Test
bgtest(m4)
## 
##  Breusch-Godfrey test for serial correlation of order up to 1
## 
## data:  m4
## LM test = 0.51249, df = 1, p-value = 0.4741
# Uji Normalitas Residual
shapiro.test(resid(m4))
## 
##  Shapiro-Wilk normality test
## 
## data:  resid(m4)
## W = 0.93208, p-value = 0.5014