Oakwood inc. manufactures end tables, armchairs, and other wood furniture products from high-quality materials. the company uses a standard costing system and isolates variances as soon as possible. the purchasing manager is responsible for controlling direct material price variances, and production managers are responsible for controlling usage variances. during november, the following results were reported for the production of american oak armchairs: units produced1,500 armchairs direct materials purchased19,000 board feet direct materials issued into production17,200 board feet standard cost per unit (12 board feet × $8)$96 per unit produced purchase price variance$2,850 unfavorable required: a. calculate the actual price paid per board foot purchased. (do not round intermediate calculations. round your answer to 2 decimal places.) b. calculate the standard quantity of materials allowed (in board feet) for the number of units produced. c. calculate the direct materials usage variance. (indicate the effect of each variance by selecting "f" for favorable, "u" for unfavorable, and "none" for no effect (i. e., zero variance).