Cost Schedule for Firm X: As shown in Exhibit 1, the marginal cost of producing the third unit is: $21,500$230$20,000$1,500Question 18 (4 points) Say these 5 firms are the only food retailers in the United States. The 3 Firm Concentration Ratio (CR3) for this industry in 2019 was 0.4 10,000 100 41 4,083.7 Can't be determined from the information given.