Karl:

## ----show-off, tidy=TRUE-------------------------------------------------
options(digits=4)
rnorm(20)
fit=lm(dist~speed, data=cars)
b=coef(fit)

## ----results='asis', echo=FALSE------------------------------------------
knitr::kable(summary(fit)$coefficients, caption='Regression coefficients.')

## ----graphics, fig.cap='A scatterplot with a regression line.'-----------
par(mar=c(4, 4, 1, .1))
plot(cars, pch = 20)
abline(fit, col = 'red')