The following regression model was developed by a professor to help the owner of a restaurant predict sales:

Sales 70.0 46.5X 1

208.5X 2

where Sales $ sales per month X

1 Advertising expenditure per month X

2

$ value of coupon Forecast sales if the owner decides to spend $500 on advertising and offers a coupon for $5 off one meal for parties of two or more in a month. Forecast sales if the owner decides to spend $400 on advertising and offers a coupon for $10 off one meal for parties of two or more in a month.