You are given the following information relating to standard and actual cost of product A. 1 unit of A needs 10 boxes of direct materials (standard usage); Standard price of one box of materials is $15; 100 units of A were produced, and 900 boxes were used (actual usage); The actual price for materials was $12 each box. Required (1) Calculate the following variances: (a) the direct material total variance; (b) the direct material price variance; (c) the direct material usage variance. (6 marks) (2) Explain the concept of materiality in variance analysis (4 marks)