Learn R: t-test

Load Packages

if (!require(haven)){
  install.packages("haven", dependencies = TRUE)
  require(haven)
}

Loading required package: haven

if (!require(tidyverse)){
  install.packages("tidyverse", dependencies = TRUE)
  require(tidyverse)
}

Loading required package: tidyverse

── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
✔ dplyr     1.1.2     ✔ readr     2.1.4
✔ forcats   1.0.0     ✔ stringr   1.5.0
✔ ggplot2   3.4.4     ✔ tibble    3.2.1
✔ lubridate 1.9.2     ✔ tidyr     1.3.0
✔ purrr     1.0.2     
── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors

Import Data

dataset.sav<- read_sav("Harry Potter Data (2).sav")

T-test

t.test(formula = FFM_14 ~ CoinFlip,
       data = dataset.sav,
       var.equal = FALSE)

    Welch Two Sample t-test

data:  FFM_14 by CoinFlip
t = -0.031063, df = 71.131, p-value = 0.9753
alternative hypothesis: true difference in means between group 1 and group 2 is not equal to 0
95 percent confidence interval:
 -0.4701102  0.4556871
sample estimates:
mean in group 1 mean in group 2 
       3.461538        3.468750 

t.test(formula = FFM_1 ~ CoinFlip,
       data = dataset.sav,
       var.equal = FALSE)

    Welch Two Sample t-test

data:  FFM_1 by CoinFlip
t = -2.419, df = 76.753, p-value = 0.01793
alternative hypothesis: true difference in means between group 1 and group 2 is not equal to 0
95 percent confidence interval:
 -1.0412385 -0.1009527
sample estimates:
mean in group 1 mean in group 2 
       3.307692        3.878788