A real estate company wants to study the relationship between house sales prices and some important predictors of sales prices. Based on data from recently sold homes in the area, the variables y=sales price (in thousands of dollars) x1=total floor area (in square feet) x2=number of bedrooms x3=distance to nearest high school (in miles) are used in a multiple regression model. The estimated model is ^y=154+0.084x1+23x2-5x3 Answer the following questions for the interpretation of the coefficient of x1 in this model. Holding the other variables fixed, what is the average change in sales price for each 100 square foot increase in floor space? Is this change an increase or decrease?