Selected Solutions (R code)
1.
(a) 
	summary(cu.lm <-(Length~factor(Species), data=cuckoo))
(c)
	par(mfrow=c(2,2))
	plot(cu.lm)
(d)
	predict(cu.lm,new=data.frame(Species=1:3),interval=”conf”)

2.
(a)
	cell.lm<-lm(Y~X1+X2+X3+X4,data=cellulose)
	library(car)
	vif(cell.lm)
(b)
	par(mfrow=c(2,2))
	plot(cell.lm)
(c)
	m1 <- lm(Y~X1+X3,data=cellulose)
	anova(cell.lm,m1)
(d)
	m2 <- lm(Y~X1+X3+I(X2+X4),data=cellulose)
	anova(cell.lm,m2)
(e)
	X5=cellulose$X3*cellulose$X4
	plot(resid(cell.lm)~resid(update(cell.lm,X5~.)))
(f)
	m3 <- lm(Y~(X1+X2+X3+X4)^2,data=cellulose)
	anova(cell.lm,m3)
(g)
	par(mfrow=c(2,2))
	plot(resid(cell.lm)~X1+X2+X3+X4,data=cellulose)
	quad.lm <- lm(Y~(X1+X2+X3+X4)^2+I(X1^2)+I(X2^2)+I(X3^2)+I(X4^2),
			 data=cellulose)
	summary(quad.lm)






3.
(a)
	n1 <- lm(LCPUE~Day+I(Day^2),data=swan)
	summary(n1)
	plot(Day,LCPUE,data=swan)
	x<-(0:300)/10000
	lines(x,predict(n1,data.frame(Day=x)))

(b)
	n2 <- nls(LCPUE~th1-2*th2*th3*Day+th3*day^2,data=swan,
		start=list(th1=0.09,th2=183,th3=-0.00013))
	summary(n2)