Question A4 The Communication Co, a medium sized company, produces a single product in its one overseas factory. For control purposes, a standard costing system was recently introduced. The standards set for the month of December were as follows: Production and sales Labour 16,000 units 4.5 hours per unit at 8.40 per hour The actual data for the month of December is as follows: Produced 15,400 units which were sold at 138.25 each. Labour: Paid an actual rate of 8.65 per hour to the labour force. The total amount paid out, amounted to 612,766. Calculate the labour rate and efficiency variances for the month of December and give a possible cause of each variance