this is one question

E7.31 (appendix) Variable and absorption costing: manufacturer Porter Ltd began operations on 1 January and achieved the following results for the year: LO7.11 Sales 36 000 units $45 per unit Selling price Manufacturing costs: Direct material Direct labour Variable overhead Fixed manufacturing overhead Selling and administrative costs: Variable Fixed Production $12 per unit $6 per unit $9 per unit $300 000 $3 per unit sold $30 000 37 500 units Required: 1. Prepare an absorption costing income statement for Porter Ltd. 2. Prepare a variable costing contribution margin statement for Porter Ltd. 3. Reconcile the differences between the profits under the two statements by: (a) identifying the areas where the statements differ (b) using the short-cut method