Costello Industries Inc. manufactures only one product. For the year ended December 31, 2012, the contribution margin increased by $31,500 from the planned level of $535,500. The president of Costello Industries Inc. has expressed some concern about such a small increase and has requested a follow-up report. The following data have been gathered from the accounting records for the year ended December 31, 2012: Actual Planned Difference-Increase(Decrease) Sales $1,102,500 $1,071,000 $31,500 Less: Variable cost of goods sold $420,000 $440,300 $-20,300 Variable selling and administrative expenses 115,500 95,200 20,300 Total $535,500 $535,500 $0 Contribution margin 567,000 $535,500 $31,500 Number of units sold 10,500 11,900 Per unit: Sales price $105 $90 Variable cost of goods sold 40 37 Variable selling and administrative expenses 11 8 1. Prepare a contribution margin analysis report for the year ended December 31, 2012