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).

y=sales x=advertising

148 12.5

55 3.7

338 21.6

994 60

541 37.6

89 6.1

126 16.8

379 41.2

The estimated regression equation to predict sales based on advertising is