Part B (12 Marks) Richards Ltd manufactures 32L convection microwave ovens. Unit data for convection microwave oven model are as follows: Convection Selling price $210 Variable costs and expenses Direct materials Direct labour 25 Manufacturing overhead 30 Selling and administrative 26 Total variable costs and $126 expenses 4! The fixed costs are: manufacturing overhead $20300, and selling and administrative expenses $9100. Required (Show all calculation) (a) Calculate the contribution margin ratio for the convection model. (2 Marks) (b) Calculate the break-even point in dollars for the convection model. (2 Marks) (c) i) Calculate the margin of safety ratio assuming that the company expects to sell 520 microwave ovens (b) Calculate the break-even point in dollars for the convection model. (2 Marks) (c) i) Calculate the margin of safety ratio assuming that the company expects to sell 520 microwave ovens from the convection model. (2 Marks) ii) Discuss how managers of Richards Ltd use this margin of safety ratio information to manage the profitability of the convection model. (4 Marks) (d) Calculate the sales (in units) necessary to make a profit of $21000 on the convection model