In a certain region, the equation  y=19.485x+86.912  models the amount of a homeowner’s water bill, in dollars, where x is the number of residents in the home. What does the slope of the equation represent in context of the situation? 1. The water bill increases by about $19 every month. 2. The water bill increases by about $19 for every additional resident in the home. 3. The water bill increases by about $87 every month. 4. The water bill increases by about $87 for every additional resident in the home.