The cost structure of Dennis's Retail Mart is dominated by variable costs with a contribution margin ratio of 0.31 and fixed costs of $84,980. Every dollar of sales contributes 31 cents toward fixed costs and profit. The cost structure of a competitor, Oakfield Convenience Store, is dominated by fixed costs with a higher contribution margin ratio of 0.69 and fixed costs of $558,440. Every dollar of sales contributes 69 cents toward fixed costs and profit. Both companies have sales of $1,214,000 for the year. Required: a. Compare the two companies' cost structures. b. Suppose that both companies experience a 25 percent increase in sales volume. By how much would each company's profits increase? Answer is not complete. Complete this question by entering your answers in the tabs below. Compare the two companies' cost structures