data(anscombe)
anscombe
attach(anscombe)

mod1=lm(y1 ~ x1)
summary(mod1)
mod2=lm(y2 ~ x2)
summary(mod2)
mod3=lm(y3 ~ x3)
summary(mod3)
mod4=lm(y4 ~ x4)
summary(mod4)

x11()
par(mfrow=c(2,2))     #make four plots on the screen
plot(x1,y1)
plot(x2,y2)
plot(x3,y3)
plot(x4,y4)

plot(x1,resid(mod1))
plot(x2,resid(mod2))
plot(x3,resid(mod3))
plot(x4,resid(mod4))

par(mfrow=c(1,1))     #return to one plot per screen
qqnorm(resid(mod1))

anova(mod1)