1. When the number of units produced increases, what is the effect on variable cost per unit? What about fixed cost per unit? What about total variable costs from all production? What about total fixed costs? 2. What does relevant range mean? Why are "fixed costs" considered "fixed" and how does the relevant range affect a cost's "fixed-ness?" 3. When using the high-low method, why might we be concerned about our estimates for variable cost per unit and total fixed costs? 4. Define contribution margin. How would management use contribution margin when making decisions for the business? 5. Are variable costs and differential costs the same thing? Why or why not