International Printer Machines OPM) builds three computer printer models: Alpha, Beta, and Gamma. Information for these three products is as follows: Alpha $250 Total Selling price per unit Variable cost per unit Expected unit sales (annual) 12,000 6,000 Gamma Sl 500 2,000 Sales mix 50 percent 40 percent 10 percent 100 percent Total annual fixed costs are Assume the sales mix remains the same at all levels of sales. Required: a) Calculate the weighted average unit contribution margin, assuming a constant sales mix. (2 marks) b) How many units of each printer must be sold to break even? (3 marks) c) i) Explain what is margin of safety (I mark) iO Calculate in sales units the margin of safety for IPM, assuming projected sales are 25,000 units? (1 mark)