Haffner Corporation uses the weighted-average method in its process costing system. Data concerning the first processing department for the most recent month are isted below Beginning vork in process inventory Unite in beginning vork in process inventory Materials costa Converaion cost 500 7,B00 9,100 85 Percent eomplete with respect to naterials Percent complete with respect to convereion Unita tarted into production during the noat h Units transferred to the next department during the month Rateriale costs added dur ing the month Convereion conts added during the month 7,000 6,100 102,700 184,000 Ending work in process investorys Unite in ending work in process inventory Percent complete with respect to materlala Percent complete with respect to eonversion 1,400 60% SO% The cost per equivalent unit for materials for the month in the first processing department is closest to: $15.92 $14.80 $13.69 $14.73