A corporation owns several companies. The strategic planner for the corporation believes dollars spent on advertising can to some extent be a predictor of total sales dollars. As an aid in long-term planning, she gathers the following sales and advertising information from several of the companies for 2013 ($ millions).
Advertising .... Sales
12.5 ...... 148
3.7 ...... 55
21.6 ...... 338
60.0 ...... 994
37.6 ...... 541
6.1 ...... 89
16.8 ...... 126
41.2 ...... 379

Develop the equation of the simple regression line to predict sales from advertising expenditures using these data.