=3/

(a) Economic breakeven point Schmidheiny 0123 Production 70.2 106 132 161 Variable costs 38.75 54.2 67.8 80.35 Contribution 31.45 51.8 64.2 80.65 Contribution as a % of sales 44.80% 48.87% 48.64% 50.09%

Fixed costs 30.95 42.7 53.3 62.15 Breakeven 69.08 87.38 109.59 124.07