### First, set the working directory where R will find the data
setwd("H:/data/User/Classes/stats02_14/Class01/Class01_2021/Wk01.R")
getwd()
## [1] "H:/data/User/Classes/stats02_14/Class01/Class01_2021/Wk01.R"
###One-sample t-test
### Read the data
# Read a csv file, named "grapenuts.csv"
grapenuts <- read.csv("grapenuts.csv")
head(grapenuts)
## ï..id GrapeNuts
## 1 1 24.13799
## 2 2 23.84806
## 3 3 23.94938
## 4 4 23.77333
## 5 5 23.91226
## 6 6 24.10736
View(grapenuts)
library(jmv)
## Warning: package 'jmv' was built under R version 4.0.3
# Two-sided test (default)
jmv::ttestOneS(
data = grapenuts,
vars = GrapeNuts,
testValue = 24,
meanDiff = TRUE,
ci = TRUE,
effectSize = TRUE,
ciES = TRUE,
desc = TRUE)
##
## ONE SAMPLE T-TEST
##
## One Sample T-Test
## -------------------------------------------------------------------------------------------------------------------------------------------------------------
## Statistic df p Mean difference Lower Upper Cohen's d Lower Upper
## -------------------------------------------------------------------------------------------------------------------------------------------------------------
## GrapeNuts Student's t -4.638404 100.0000 0.0000107 -0.06000000 -0.08566363 -0.03433637 -0.4615385 -0.6657131 -0.2552718
## -------------------------------------------------------------------------------------------------------------------------------------------------------------
## Note. H<U+2090> population mean <U+2260> 24
##
##
## Descriptives
## -----------------------------------------------------------------------
## N Mean Median SD SE
## -----------------------------------------------------------------------
## GrapeNuts 101 23.94000 23.90311 0.1300000 0.01293548
## -----------------------------------------------------------------------
# One-sided test (expect our mean to be less)
jmv::ttestOneS(
data = grapenuts,
vars = GrapeNuts,
testValue = 24,
hypothesis = "lt",
meanDiff = TRUE,
ci = TRUE,
effectSize = TRUE,
ciES = TRUE,
desc = TRUE)
##
## ONE SAMPLE T-TEST
##
## One Sample T-Test
## -------------------------------------------------------------------------------------------------------------------------------------------------------
## Statistic df p Mean difference Lower Upper Cohen's d Lower Upper
## -------------------------------------------------------------------------------------------------------------------------------------------------------
## GrapeNuts Student's t -4.638404 100.0000 0.0000053 -0.06000000 -Inf -0.03852407 -0.4615385 -0.6657131 -0.2552718
## -------------------------------------------------------------------------------------------------------------------------------------------------------
## Note. H<U+2090> population mean < 24
##
##
## Descriptives
## -----------------------------------------------------------------------
## N Mean Median SD SE
## -----------------------------------------------------------------------
## GrapeNuts 101 23.94000 23.90311 0.1300000 0.01293548
## -----------------------------------------------------------------------