1. The explanatory variable defines the x-axis in a scatterplot.
2. In a plot of income (the response) versus education (the explanatory variable) for managers, managers with the lowest levels of education are at the right-hand side of the figure.
3. The presence of a pattern in a scatterplot means that values of the response increase with the values of the explanatory variable.
4. The visual test for association is used to decide whether a plot has a real or imagined pattern.
5. A line with positive slope describes a linear pattern with a positive direction.
6. A company has learned that the relationship between its advertising and sales shows diminishing marginal returns. That is, as it saturates consumers with ads, the benefits of increased advertising diminish. The company should expect to find linear association between its advertising and sales.