1. Download the smelter cost data and open it in Excel. 2. Calculate the marginal cost for each smelter by adding a new row that sums the appropriate cost items. 3. Sort the smelters according to the measure of marginal costs you created in step 2. 4. Create a measure of total cumulative capacity in each column. This will tell you how much capacity is more efcient than any particular plant. 5. Create a graph of the supply curve by making an HKY' scatter plot of the marginal cost and cumulative capacity measures you created above