Davis1 <- read.table("c:/temp/davis.txt",header=T,na.string=".")
names(Davis1)

 # change two misrecorded values
Davis1[12,]$weight <- 57
Davis1[12,]$height <- 166

plot(Davis1$reportedWeight,Davis1$weight)

Davis1.lm1 <- lm(weight ~ reportedWeight, data=Davis1)

summary(Davis1.lm1)
anova(Davis1.lm1)

 # automatically generates several useful plots
par(mfrow=c(2,2)) 
plot(Davis1.lm1)
par(mfrow=c(1,1))