QUESTION 4 The underlisted data relate to actual output, costs and variances for the monthly accounting period of a company that makes only one product. Opening and closing work in progress were the same. Variances: GH Direct materials price 30000 F Direct materials usage 18000 A Direct labour rate 16000 A Direct labour efficiency 32000 F Variable production overhead expenditure 12000 A Variable production overhead efficiency 8000 F Variable production overhead varies with labour hours worked. A standard marginal costing system is operated. Actual production of product BM 36,000 units Actual costs incurred: Direct materials purchased and used (300,000 kg) GH420,000 Direct wages for 64000 hours GH272,000 Variable production overhead GH76,000 Required: (a) (i) Calculate the standard cost of materials and standard rate per labour hour. (ii) Prepare a standard product cost sheet for one unit of product BM. (b) Explain the possible causes of the following variances: (i) Material price variance (ii) Material usage variance (iii) Wage rate variance (iv) Labour efficiency variance