Question: Correlation and regression. If the correlation between two variables x and y is r = 0, there is no straight-line relationship between the variables. It turns out that the correlation is 0 exactly when the slope of the least-squares regression line is 0. Explain why slope 0 means that there is no straight-line relationship between x and y. Start by drawing a line with slope 0 and explaining why in this situation x has no value for predicting y.