Oversites, Inc, uses a process costing system. The company's work-in-process inventory account at February 28th consists of 70,000 units which are 100% complete with respect to materials and 80% complete with respect to conversion costs. If the balance in the work-in-process inventory account is $546,000 and the cost per equivalent unit for conversion costs is $6.00, what is the cost per equivalent unit for materials