\begin{Schunk}
\begin{Sinput}
 mycols <- c("blue", "red")
 plot(statusquo ~ income, data = Chile, xlab = "Income (1,000,000s pesos)", ylab = "Status Quo Support", col = mycols[Chile$sex], cex = 0.7 )
 incomeSeq <- seq(min(Chile$income, na.rm = TRUE), 
                   max(Chile$income, na.rm = TRUE), length.out = 5)
 newdat <- expand.grid(income = incomeSeq, sex = levels(Chile$sex))
 newdat$pred <- predict(chmod3, newdata = newdat)
 by(newdat, newdat$sex, function(datsub) lines(pred ~ income, dat =  datsub, col = mycols[datsub$sex]))
 legend("topleft", levels(newdat$sex), col = mycols, lty = 1, bg = "white")
\end{Sinput}
\end{Schunk}
