The following data relate to direct labor costs for the current period: Standard costs Actual costs 6,800 hours at $11.90 6,400 hours at $10.20 The direct labor rate variance is a. $15,640 unfavorable b. $10,880 favorable c. $15,640 favorable Od. $4,760 favorable Mason Corporation had $1,172,000 in invested assets, sales of $1,293,000, operating income amounting to $207,000, and a desired minimum return on investment of 13% The residual income for Mason Corporation is $54,640 b. $76,4961 Oc. 50 d. ($5,100)