22.04 ders

library(car)

## Loading required package: carData

library(tidyverse)

## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr     1.1.4     ✔ readr     2.1.5
## ✔ forcats   1.0.1     ✔ stringr   1.6.0
## ✔ ggplot2   4.0.1     ✔ tibble    3.3.0
## ✔ lubridate 1.9.4     ✔ tidyr     1.3.2
## ✔ purrr     1.2.0

## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ✖ dplyr::recode() masks car::recode()
## ✖ purrr::some()   masks car::some()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors

library(lsr) #LEVENE TESTİ İÇİN

set.seed(1923) #TEKRARLANABİLİRLİK İÇİN

deney_grubu<-rnorm(50, mean=45,sd=8)#deney grubu
kontrol_grubu<-rnorm(50,mean=52,sd=8)#kontrol grubu

fare_verisi<-data.frame(grup=rep(c("deney","kontrol"),each=50)) %>% 
  mutate(süre=round(c(deney_grubu,kontrol_grubu),2))

head(fare_verisi)

##    grup  süre
## 1 deney 39.81
## 2 deney 45.56
## 3 deney 53.49
## 4 deney 56.08
## 5 deney 52.47
## 6 deney 42.59

tail(fare_verisi)

##        grup  süre
## 95  kontrol 46.23
## 96  kontrol 59.74
## 97  kontrol 52.52
## 98  kontrol 50.93
## 99  kontrol 62.96
## 100 kontrol 64.11

fare_istatistiği<-fare_verisi %>% 
  group_by(grup) %>% 
  summarise(N=n(),
            ortalama=mean(süre),
            standart_sapma=sd(süre))

print(fare_istatistiği)

## # A tibble: 2 × 4
##   grup        N ortalama standart_sapma
##   <chr>   <int>    <dbl>          <dbl>
## 1 deney      50     45.2           8.81
## 2 kontrol    50     52.4           7.92

fare_verisi %>% 
  group_by(grup) %>% 
  summarise(shapiro_p=shapiro.test(süre)$p.value)

## # A tibble: 2 × 2
##   grup    shapiro_p
##   <chr>       <dbl>
## 1 deney       0.409
## 2 kontrol     0.810

leveneTest(süre~grup,data=fare_verisi)

## Warning in leveneTest.default(y = y, group = group, ...): group coerced to
## factor.

## Levene's Test for Homogeneity of Variance (center = median)
##       Df F value Pr(>F)
## group  1  0.5295 0.4686
##       98

sonuc<-t.test(süre~grup,data=fare_verisi,var.equal=TRUE)
print(sonuc)

## 
##  Two Sample t-test
## 
## data:  süre by grup
## t = -4.3425, df = 98, p-value = 3.436e-05
## alternative hypothesis: true difference in means between group deney and group kontrol is not equal to 0
## 95 percent confidence interval:
##  -10.601619  -3.951181
## sample estimates:
##   mean in group deney mean in group kontrol 
##               45.1614               52.4378

cohensD(süre~grup,data=fare_verisi)

## [1] 0.8685009