Ruby Company produces a chair that requires 4 yards of material per unit. The standard price of one yard of material is $11.90. During the month, 5,100 chairs were manufactured, using 20,000 yards at a cost of $12.61 per yard. Enter favorable variances as negative numbers. (a) Determine the price variance. (b) Determine the quantity variance. (c) Determine the cost variance. Favorable Unfavorable