An article on the cost of housing in california that appeared in the san luis obispo tribune† included the following statement: "in northern california, people from the san francisco bay area pushed into the central valley, benefiting from home prices that dropped on average $4000 for every mile traveled east of the bay area." if this statement is correct, what is the slope of the least-squares regression line, ŷ = a + bx, where y = house price (in dollars) and x = distance east of the bay (in miles)?