The county assessor is studying housing demand and is interested in developing a regression model to estimate the market value (i.e., selling price) of residential property within his jurisdiction. The assessor suspects that the most important variable affecting selling price (measured in thousands of dollars) is the size of house (measured in hundreds of square feet). He randomly selects 15 houses and measures both the selling price and size, as shown in the following table.

Complete the table and then use it to determine the estimated regression line.