Untitled

library(wooldridge)
data(wage1)
head(wage1)
names(wage1)
structure(wage1)
summary(wage1)
ml1<-lm(wage~educ,data=wage1)
summary(ml1)
ml2<-lm(wage~educ+exper+tenure,data=wage1)
summary(ml2)
plot(fitted.values(ml1),residuals(ml1))
xlab="fitted.values"
ylab="residual"
main="fitted.values vs residuals"
abline(h=0,col"red"")
plot(fitted.values(ml2),residuals(ml2))
xlab="fitted.values"
ylab="residuals"
main="fitted.values vs residuals"