Case 2: Muna Manufacturing has the following standard cost for manufacturing: Per completed piece Materials: 5 kg a RO 4.20 Labor: 3 hours @ RO 3 The Production Schedule for the month of March 2020 required completion of 5,000 pieces. However, 5,120 pieces were completed. Purchases for the month March 2020 amounted to 30,000 Kg of material at the total invoice price of RO 135,000 Production records for the month of March 2020 showed the following actual results. Materials requisitioned and used 25,700 Kg Direct Labor - 15,150 hours RO 48,480. The manager of Muna Manufacturing requested you to: (4 + 6 = 10 Marks) a. Calculate labor variances and comment on the results