Question

How can I do one-way ANOVA in RStudio?

Answer 1

Sol

tthere is an nbuilt datset in R iris.

It has 150 observations and 5 variables.

variable names are:

"Sepal.Length" "Sepal.Width" "Petal.Length" "Petal.Width" "Species"

species has 3 levels namely setosa", "versicolor", "virginica

we want to performNAOVA that

H0:all species mean sepal length are equal.

H1:atleast one of the species mean sepal length is different.

with aov function in R you will do one way anova

and with summary function you get anova table

Rcode to do anova is

dim(iris)
names(iris)
unique(iris$Species)
iris$Species <- ordered(iris$Species,
levels = c("setosa", "versicolor", "virginica"))
result.anova <- aov(Sepal.Length ~ Species, data = iris)
# Summary of the analysis
summary(result.anova)

Df Sum Sq Mean Sq F value Pr(>F)   
Species 2 63.21 31.606 119.3 <2e-16 ***
Residuals 147 38.96 0.265

Intrepretation

F(2,147)=119.3

p=<2e-16 ***

p=0.0000

p<0.05

we conclude that atleast one of the species sepal length is different