In this example we use the typical sales price of homes in a random sample of us counties (recorded with units as $1000 per square foot) to predict the typical rental cost in the county (in units of $ per square foot) . y: the typical rental cost in the county ($ per square foot). x: the typical sales price of properties in the county ($1000 per square foot). assume we compare counties a and b. county a has a typical sales price of properties at $45 per square foot higher than county b. assume the regression equation is latex: \hat{y}