At a price of $48, the estimated monthly sales of a product are 18,000 units. Variable expenses include manufacturing costs of $27 and distribution costs of $9. Fixed expenses are $60,000 per month. (1) Prepare the contribution margin income statement. (2) Determine the margin of safety in units. (3) Compute the contribution margin ratio. (4) Determine the sales revenues that ensure the after-tax profit $140,000 assuming the tax rate is 30%. (5) Determine the target units that ensure the before-tax profit $140,000 assuming the tax rate is 30%