set.seed(1) DF <- data.frame("Y" = rnorm(100)) DF$D <- ifelse(DF$Y > 0, 1, 0) dummy_mod <- lm(Y ~ D, data = DF) # Replace the `???` by the correct values plot(x = ??? , y = ???, pch = 20, cex = 1, col = "Steelblue", xlab = expression(D[i]), ylab = "Test Score", main = "Dummy Regression" ) # add the regression line plot(x = DF$D , y = DF$Y, pch = 20, cex = 1, col = "Steelblue", xlab = expression(D[i]), ylab = "Test Score", main = "Dummy Regression" ) abline(dummy_mod) test_predefined_objects(c("DF","dummy_mod")) test_function("abline") test_function("plot", args = c("x", "y")) success_msg("Nice! Clearly, a line is not a suitable way to think of this model!")