The Z Corporation produces and markets two types of electronic calculators: Model 11 and Model 12. The following data were gathered on activities last month:

	Model 11	Model 12
Sales in units	5,000	3,000
Selling price per unit	$50	$100
Variable production costs per unit	$10	$26
Traceable fixed production costs	$100,000	$150,000
Variable selling expenses per unit	$5	$6
Traceable fixed selling expenses	$5,000	$7,500
Allocated division administrative expenses	$50,000	$60,000

Required: (7 marks) a. Prepare a segmented income statement in the contribution format for last month, showing both "Amount" and "Percent" columns for the company as a whole and for each model. (5 marks) b. Why might it be very difficult to calculate separate break-even sales for each model? (2 marks)