Mba 4Cornerstone Svn MacBuilding CornerstoneACTS 4:11 11 This is the ‘stone which was rejected by you builders, which has become the chief cornerstone.’Cornerstone Exercise 4.1 (Algorithmic) Applied Overhead and Unit Overhead Cost: Plantwide Rates. Seco, Inc., produces two types of clothes dryers: deluxe and regular. Seco uses a plantwide rate based on direct labor hours to assign its overhead c..