library(alr4)

m1 <- lm(lpres ~ bp, data=Forbes)
m1
summary(m1)
names(m1)
m1$coefficients
m1$residuals
s1 <- summary(m1)
s1
names(s1)
s1$call
s1$terms
s1$residuals

Forbes1 <- Forbes[, c(1, 3)] # select columns 1 and 3
Forbes[, c("bp", "lpres")]
Forbes1
Forbes
print(fmeans <- colMeans(Forbes1))
(fmeans <- colMeans(Forbes1))
fmeans <- colMeans(Forbes1)
?colMean
(fcov <- (17 - 1) * cov(Forbes1))
crossprod(scale(Forbes1, center=TRUE, scale=FALSE))
xbar <- fmeans[1]
ybar <- fmeans[2]
SXX <- fcov[1,1]
SXY <- fcov[1,2]
SYY <- fcov[2,2]
xbar
ybar
SXX
SXY
SYY
betahat1 <- SXY/SXX
betahat0 <- ybar - betahat1 * xbar
betahat1
betahat0
m1
print(c(betahat0 = betahat0, betahat1 = betahat1), digits = 4)

(x<-Forbes$bp)
(y<-Forbes$lpres)
Xbar<-mean(x)
Ybar<-mean(y)
Xbar
Ybar
sxx<-sum((x-Xbar)^2)
sxx
SXX
syy<-sum((y-Ybar)^2)
syy
SYY
sxy<-sum((x-Xbar)*(y-Ybar))
sxy
SXY
(beta1hat <- sxy/sxx)
(beta0hat <- Ybar - beta1hat * Xbar)
betahat1
betahat0