#-----------------------------------------------------------------------------
# BAB 7 UJI KESAMAAN VARIANS POPULASI
#-----------------------------------------------------------------------------
##############################################################################
# TUGAS STATISTIK SOSIAL #
# Nama: Chika Shelomita #
# NIM: 2502056032 #
##############################################################################
#----------------------------------------------------------------------------------
# Contoh Kasus Uji Kesamaan Varians Populasi dengan
# Uji Levene (Contoh Perhitungan)
#----------------------------------------------------------------------------------
qf(.95, df1=2, df2=15)
## [1] 3.68232
#----------------------------------------------------------------------------------
# Penyelesaian dalam R untuk Uji Kesamaan Varians Populasi dengan Uji Levene
#----------------------------------------------------------------------------------
varians=read.csv("D:/STATSOS/varians.csv", sep = ";")
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
data(varians)
## Warning in data(varians): data set 'varians' not found
levene.test(varians[,"Nilai"], varians[,"Kelas"], location="median",correction.method="zero.correction") #Sesuai dengan Minitab
##
## 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") #Sesuai dengan SPSS
##
## 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
#----------------------------------------------------------------------------------
# Contoh Kasus 2, Uji Kesamaan Varians Populasi dengan Uji Levene
# (Contoh Perhitungan dan Penyelesaian dengan R)
#----------------------------------------------------------------------------------
simpan=read.csv("D:/STATSOS/varians2.csv", header=TRUE, sep=";") #membaca data
simpan
## Nilai Kelas
## 1 30 1
## 2 40 1
## 3 50 1
## 4 60 1
## 5 70 1
## 6 80 1
## 7 90 1
## 8 10 2
## 9 20 2
## 10 30 2
## 11 40 2
## 12 50 2
## 13 60 2
## 14 70 2
library(doBy)
summaryBy(Nilai ~ Kelas, data = simpan, FUN = function(x)
{ c(ratarata = mean(x), varians = var (x), jumlah=sum(x) ) } )
## Kelas Nilai.ratarata Nilai.varians Nilai.jumlah
## 1 1 60 466.6667 420
## 2 2 40 466.6667 280
qf(0.95, df1=1, df2=12)
## [1] 4.747225
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 = 1.4336e-32, p-value = 1