Looking at the model of long-term and short-term aggregate demand and aggregate supply, why is the aggregate-demand curve sloping downward? explain why the long-term aggregate-supply curve is vertical? explain why the short-term aggregate-supply curve is upward sloping? what might shift the aggregate-demand curve to the left? what are the short-term and long-term effects of such a shift on output and the price level?

Shelby company produces three products: product x, product y, and product z. data concerning the three products follow (per unit): product x product y product z selling price $ 85 $ 65 $ 75 variable expenses: direct materials 25.50 19.50 5.25 labor and overhead 25.50 29.25 47.25 total variable expenses 51.00 48.75 52.50 contribution margin $ 34.00 $ 16.25 $ 22.50 contribution margin ratio 40 % 25 % 30 % demand for the company’s products is very strong, with far more orders each month than the company can produce with the available raw materials. the same material is used in each product. the material costs $8 per pound, with a maximum of 4,400 pounds available each month. required: a. compute contribution margin per pound of materials used. (round your intermediate calculations and final answers to 2 decimal places.) contribution margin per pound product x $ product y $ product z $ b. which orders would you advise the company to accept first, those for product x, for product y, or for product z? which orders second? third? product x product y product z