Interpreting regression data. A marketing manager of a company used a pocket calculator to estimate the relation between sales dollars for the past three years and monthly advertising expenditures (the independent variable). The regression results indicated the following equation:
Sales Dollars ¼ $97,000 - ð1:45 x Advertising Dollars.
Do these results imply that advertising hurts sales? Why would there appear to be a negative relation between advertising expenditures and sales?