Q4 (a) Turnstone Brothers Ltd. manufactures COVID testing kits. The company uses standard costing to control its costs. The labour standards to manufacture one test kit are as follows: Standard time Standard hourly rate 18 minutes 12 During the month of March, 5,400 direct labour hours were recorded for manufacturing 20,000 test kits. The total direct labour cost was 73,600 for March. (i) What total direct labour cost should have been incurred in the month? How much does it differ from the actual direct labour cost incurred? [6 marks] (ii) Calculate labour rate and labour efficiency variances. [7 marks] (b) Standards are a useful tool for management by exception. They can also have some issues associated with them.' Discuss the above comment. [12 marks]