ECSENOMICS Add All Firms' Supply Curves to Derive Market Supply T63 Figure 8-4 (a) Firm As Supply (b)Firm Bs Supply (e) Market Supply 60 Market 40 supply curve 20 20 S 51015 Q=9A+9B Quantity A(thousands) Quantity B(thousands) Total quantity(thousands) McGraw-Hilllrwin CopyrightC 2001 The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/Irwin Copyright © 2001 The McGraw-Hill Companies, Inc. All rights reserved. Add All Firms’ Supply Curves to Derive Market Supply T-63 Figure 8-4