Why is the Form W-2 needed in order to file a tax return?

Pestiferous manufacturing produces a chemical pesticide and uses process costing. there are three processing departmentslong dash​mixing, ​refining, and packaging. on january​ 1, the first departmentlong dashmixinglong dashhad no beginning inventory. during​ january, 48,000 fl. oz. of chemicals were started in production. of​ these, 40,000 fl. oz. were​ completed, and​ 8,000 fl. oz. remained in process. in the mixing​ department, all direct materials are added at the beginning of the production​ process, and conversion costs are applied evenly throughout the process. at the end of​ january, the equivalent unit data for the mixing department were as​ follows: units equivalent units equivalent units units to be accounted for direct materials costs conversion costs completed and transferred out ​40,000 ​40,000 ​40,000 ending​ work-in-process* ​8,000 ​8,000 ​3,520 ​48,000 ​48,000 ​43,520 ​* percent complete for conversion​ costs: 44% in addition to the​ above, the cost per equivalent unit were​ $1.35 for direct materials and​ $5.30 for conversion costs. using this​ data, calculate the full cost of the ending wip balance in the mixing department. the​ weighted-average method is used.