Orth and Associates is a small firm that provides structural engineering services for its clients. The company performs structural engineering services for both residential and commercial buildings. Last year, total overhead costs of $330,000 were allocated based on direct labor costs. A total of $300,000 in direct labor costs were incurred in the following areas: $120,000 in the residential segment and $180,000 in the commercial segment. Direct materials used were negligible and are included in overhead costs. Sales revenue totaled $450,000 for residential services and $330,000 for commercial services. The management of Orth and Associates would like to use activity-based costing to allocate overhead rather than a plantwide