The following data are from the accounting records of Niles Castings for year 2.

Units produced and sold		84,000
Total revenues and costs
Sales revenue	$	280,000
Direct materials costs		62,000
Direct labor costs		33,000
Variable manufacturing overhead		19,000
Fixed manufacturing overhead		49,000
Variable marketing and administrative costs		11,500
Fixed marketing and administrative costs		31,000

Required:

a. Prepare a gross margin income statement.

b. Prepare a contribution margin income statement.