# Note: R is case sensitive!

      # Here we plot the histogram of the variable Head:
hist(X$Head)
      # regress X$Head on X$Chest and store the results:
result <- lsfit(X$Head,X$Chest)
      # print the regression results:
ls.print(result)
      # pretty obvious what this does:
plot(X$Head,X$Chest)
      # add the regression line to the plot:
abline(result)
      # add a nonparametric regression line (a smoother):
lines(lowess(X$Head,X$Chest), col=2)