# R-program for Supplementary Exercise 10.17 of IPS7e

phys <- read.csv("r:/Chapter 10/ex10_017.csv")
# scatterplot with fitted line
plot(phys$HR, phys$VO2)
abline( lsfit(phys$HR, phys$VO2))

# simple linear regression
phys.reg <- lm(VO2 ~ HR, data=phys)
summary(phys.reg)
anova(phys.reg)

# prediction
new <- data.frame( HR=c(96,115))
phys.pred <- predict(phys.reg, new, interval="prediction"); phys.pred
phys.ci <- predict(phys.reg, new, interval="confidence"); phys.ci