Investigation of Variances Sommers Company uses the following rule to determine whether materials usage variances should be investigated: A materials usage variance will be investigated anytime the amount exceeds the lesser of $12,000 or 10% of the standard cost. Reports for the past five weeks provided the following information: Week MUV Standard Materials Cost 1 $10,500 F $120,000 2 10,700 F 100,500 3 9,000 U 120,000 4 13,500 U 127,500 5 10,500 U 103,500 Required: Using the rule provided, identify the cases that will be investigated. Week 1 Week 2 Week 3 Week 4 Week 5 2. CONCEPTUAL CONNECTION Suppose investigation reveals that the cause of an unfavorable materials usage variance is the use of lower-quality materials than are normally used. Who is responsible