Tesla motors’ cost structure is dominated by fixed costs with a contribution margin ratio of .6 and fixed costs of $380,000. every dollar of sales contributes 60 cents towards fixed costs and profit. general motors’ cost structure is dominated by variable costs with a lower contribution margin ratio of .25 with a fixed cost of $150,000. every dollar of sales contributes 25 cents toward fixed costs and profit. both companies have monthly sales of $750,000. suppose both companies experience a 10 percent decline in sales volume. by how much would each company’s operating income decrease?