pdf("E:\\sta4211\\KNNL_TA17_04.pdf") piece <- read.table("http://www.stat.ufl.edu/~winner/sta4211/datasets/CH17TA04.txt",header=F, col.names=c("y","hours","employee")) attach(piece) x.hours <- 2*hours+4 piece.aov <- aov(y~factor(hours)) summary(piece.aov) TukeyHSD(piece.aov,'factor(hours)') piece.quad <- lm(y ~ x.hours + I(x.hours^2)) summary(piece.quad) anova(piece.quad) anova(piece.quad,piece.aov) plot(x.hours,y,xlab="Hours of Training",ylab="Number of Acceptable Units") xs <- seq(6,12,.1) lines(xs,coef(piece.quad)[1]+coef(piece.quad)[2]*xs+coef(piece.quad)[3]*xs^2) dev.off()