Assume that a company's planned level of activity was 3,500 units and its actual level of activify was 4,000 units. The spending variance for one of its mixed expenses was $900 favorable and its activity variance was $200 unfavorable. The total amount of this mixed cost included in the planning budget was $12,000. What is the actual total amount of this mixed expense? Multiple Choice $11,300 $10,900 $13,100 $11700