Part B (12 Marks) Ben Ltd manufactures ducted air conditioners. Unit data for ducted air conditioner model are as follows: Air conditioner model Selling price $6300 Variable costs and expenses Direct materials 10401 Direct labour 2000 Manufacturing overhead 1000 Selling and administrative 1000 Total variable costs and expenses $5040 The fixed costs are: manufacturing overhead $200 300, and selling and administrative expenses $41 700. Required: (a) Calculate the contribution margin ratio for the ducted air conditioner model. (3 Marks) (b) Calculate the break-even point in dollars for the ducted air conditioner model. (3 Marks) (c) (i) Calculate the margin of safety ratio assuming that the company expects to sell 420 ducted air conditioner models. (2 Marks) (ii) Discuss how managers of Ben Ltd use this margin of safety ratio information to manage the profitability of the ducted air conditioner model? (4 Marks)