The following is Arka Corporation's contribution format income statement for last month Total Per Unit $1,200,000 $340,000 $350,000 Direct labor (variable).... Manufacturing overhead: Variable Fixed.... $110,000 $155,600 Selling & administrative: Variable Fixed 140,000 $96,756 .... The company has no beginning or ending inventories, and produced and sold 25,000 units during the month. Required: Compute the following items - show your calculations: a. Unit contribution margin b. Contribution margin ratio (round to three significant digits.)