The production manager at company XYZ needs to prepare forecasts of product demand in order to plan for appropriate production quantities. In the past, demand for the product has been strongly dependent on the effort put in advertising and promoting the product. To show this, the marketing manager has compiled the data below on sales (in thousands of units) and advertising budget (in thousands of $) over the past 5 months. The marketing budget allocated to this product in the next month is $3,500. Use linear regression to develop an equation for the relationship between unit sales and advertising $, and generate a forecast for this product. months sales advertising (thousands of units) ( thousands of $) 1 264 50 2 116 26 3 165 28 4 101 20 5 209 40 6 ? 35