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# TUGAS : STATISTIK SOSIAL                                                     #
# NAMA  : MAULIDA SYIFA                                                        #
# NIM   : 2502056010                                                           #
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################################### BAB 7 ######################################

#UJI KESAMAAN VARIANS POPULASI#

#Uji Kesamaan Varians Populasi dengan Uji Levene#

qf(.95, df1=2, df2=15)
## [1] 3.68232
#Penyelesaian dalam R untuk Uji Kesamaan Varians Populasi dengan Uji Levene (1)#

varians = read.csv("varians.csv")
varians
##    Nilai Kelas
## 1     70     1
## 2     80     1
## 3     87     1
## 4     77     1
## 5     80     1
## 6     80     2
## 7     85     2
## 8     70     2
## 9     77     2
## 10    85     2
## 11    60     2
## 12    80     2
## 13    70     3
## 14    87     3
## 15    90     3
## 16    77     3
## 17    76     3
## 18    87     3
library(car)
## Loading required package: carData
leveneTest(varians$Nilai, varians$Kelas)
## Warning in leveneTest.default(varians$Nilai, varians$Kelas): varians$Kelas
## coerced to factor.
## Levene's Test for Homogeneity of Variance (center = median)
##       Df F value Pr(>F)
## group  2  0.4267 0.6604
##       15
library(Rcmdr)
## Loading required package: splines
## Loading required package: RcmdrMisc
## Loading required package: sandwich
## Loading required package: effects
## Registered S3 method overwritten by 'lme4':
##   method           from
##   na.action.merMod car
## lattice theme set by effectsTheme()
## See ?effectsTheme for details.
## The Commander GUI is launched only in interactive sessions
## 
## Attaching package: 'Rcmdr'
## The following object is masked from 'package:base':
## 
##     errorCondition
leveneTest(varians$Nilai, varians$Kelas)
## Warning in leveneTest.default(varians$Nilai, varians$Kelas): varians$Kelas
## coerced to factor.
## Levene's Test for Homogeneity of Variance (center = median)
##       Df F value Pr(>F)
## group  2  0.4267 0.6604
##       15
library(lawstat)
## 
## Attaching package: 'lawstat'
## The following object is masked from 'package:car':
## 
##     levene.test
levene.test(
  varians[, "Nilai"],
  varians[, "Kelas"],
  location = "median",
  correction.method = "zero.correction"
)
## 
##  Modified robust Brown-Forsythe Levene-type test based on the absolute
##  deviations from the median with modified structural zero removal method
##  and correction factor
## 
## data:  varians[, "Nilai"]
## Test Statistic = 0.4372, p-value = 0.6557
levene.test(
  varians[, "Nilai"],
  varians[, "Kelas"],
  location = "mean",
  correction.method = "zero.correction"
)
## 
##  Classical Levene's test based on the absolute deviations from the mean
##  ( zero.correction not applied because the location is not set to median
##  )
## 
## data:  varians[, "Nilai"]
## Test Statistic = 0.64903, p-value = 0.5366
#Penyelesaian dalam R untuk Uji Kesamaan Varians Populasi dengan Uji Levene (2)#

simpan = read.csv("varians2.csv", header = TRUE, sep = ",") #membaca data
simpan
##   Nilai Kelas
## 1    30    10
## 2    40    20
## 3    50    30
## 4    60    40
## 5    70    50
## 6    80    60
## 7    90    70
library(doBy)
summaryBy(Nilai~kelas, data=simpan, FUN = function(x)
{c(ratarata=mean(x), varians=var(x), jumlah=sum(x)   )})
##   Nilai.ratarata Nilai.varians Nilai.jumlah
## 1             60      466.6667          420
qf(0.95, df1=1, df2 = 12)
## [1] 4.747225
simpan = read.csv("varians2.csv", header = TRUE, sep = ",") #membaca data
simpan
##   Nilai Kelas
## 1    30    10
## 2    40    20
## 3    50    30
## 4    60    40
## 5    70    50
## 6    80    60
## 7    90    70
library(lawstat)
data(simpan)
## Warning in data(simpan): data set 'simpan' not found
levene.test(simpan[,"Nilai"], simpan[,"Kelas"], location="mean", correction.method="zero.correction")
## 
##  Classical Levene's test based on the absolute deviations from the mean
##  ( zero.correction not applied because the location is not set to median
##  )
## 
## data:  simpan[, "Nilai"]
## Test Statistic = NaN, p-value = NA