Consider the following Data for Interface Unit during Apr 20x2 19X9 20X0 20X1 Planned Production (units) Planned opening 28 000 ? 32 200 4200 ? ? inventory (units) Planned closing 2 800 5 040 ? inventory (units) Planned sales ? 31 600 33 040 units Budgeted fixed 336 000 336 000 336 000 manufacturing overheads Budgeted machine 700 0000 700 000 700 000 hours Budgeted direct 420 000 420 000 420 000 material cost Actual cost data per year: 19X9 20X0 20X1 Direct material R33.60 R33.60 R33.60 cost per unit Direct labor cost R42.00 R42.00 R42.00 per unit Variable R8.40 R8.40 R8.40 manufacturing overheads per unit Sales 14% 14% 14% Commission Total variable 176 400 ? ? administration cost