Crombie Company uses two raw materials, X and Y, in the manufacture of its only product: Amber. Both materials are very close substitutes. The standard proportions for the manufacture of a unit of Amber are 6 units of X and 4 units of Y. The unit standard prices of X and Y are $16 and $20, respectively. During the month of August, the company used 3,000 units of X and 1,800 units of Y to produce 460 units of Amber. Required: a) Calculate the following variances for raw materials X and Y: (8 marks) (i) Quantity variances. (ii) Mix variances. (iii) Yield variances b) Suppose you are made aware that the assistant production manager recommended the departure from the standard mix. Should the assistant manager be commended? Explain (2 marks)