2. An industry consists of 3 firms with sales of $225,000; $45,000; and $315,000. 2.1. (5 points) Calculate the Herfindahl-Hirschman index (HHI). 2.2. (5 points) Calculate the four-firm concentration ratio (C 4). 2.3. (5 points) Based on the Department of Justice merger rules discussed in class, does the Department of Justice considers this industry unconcentrated, moderately concentrated, or highly concentrated