install.packages("mvoutlier")
library(mvoutlier)

outliers <- aq.plot(mtcars[c("mpg","disp","hp","drat","wt","qsec")])
outliers # show list of outliers

par(mfrow=c(1,1))

attach(mtcars)
qqnorm(mpg)
qqline(mpg)

# Bartlett Test of Homogeneity of Variances
bartlett.test(y~G, data=mydata)

# Figner-Killeen Test of Homogeneity of Variances
fligner.test(y~G, data=mydata)