Barlett Ltd manufactures garden storage sheds. It uses a standard costing system for one of its products. Predetermined manufacturing overhead rate is calculated based on direct labour hours. The standard direct labour cost is 15 hours per unit at $16.00 per hour, and the standard direct material cost is 62 kg per unit at $8.00 per kg. Other information is as follows: Budgeted Actual Monthly production 520 units 498 units Direct materials (kg) 30,200 kg Direct materials ($) $249,150 Direct labour (hours) 7,540 hrs Direct labour ($) $114,608 Fixed overhead per month $59,280 $61,200 Variable overhead per month $32,760 $30,410 "Budgeted monthly production is the same throughout the whole year. Required: (a) (12 marks) Calculate the following variances and label them as favourable (F) or unfavourable (U). Note: To obtain maximum marks, please set out your answers clearly (1) Direct materials price and quantity variances. (1) Direct labour price and quantity variances. (ili) Total overhead variance (iv) Variable overhead spending and efficiency variances. (b) (2 marks) Barlett requires the production manager to explain and investigate all variances calculated above. Provide two reasons why this requirement may not be a good idea. Your explanation must be specific to the company