custom_seed(123) X <- runif(100, 0, 3) Y <- exp(-X) + rnorm(100, 0, .05) plot(Y ~ X) # compute the correlation between X and Y # compute the correlation between X and Y cor(X, Y) test_output_contains("cor(X, Y") success_msg("Correct! The correlation is able to capture the negative relationship between both variables. However it only measures linear dependencies, whereas the dependency here is clearly nonlinear (exponential).")