Ruby Company produces a chair that requires a standard 6 yards of material per unit. The standard price of one yard of material is $11.50. During the month, 4,800 chairs were manufactured, using 29,100 yards at a cost of $10.92 per yard. Determine the (a) direct materials price variance, (b) direct materials quantity variance, and (c) total direct materials cost variance. Enter favorable variances as negative numbers. a. Direct materials price variance b. Direct materials quantity variance c. Total direct materials cost variance