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Sheffield Company's standard labor cost of producing one unit of Product DD is 3.90 hours at the rate of $13.20 per hour. During August, 40,800 hours of labor are incurred at a cost of $13.30 per hour to produce 10,300 units of Product DD. (a) Compute the total labor variance. Total labor variance $ (b) Compute the labor price and quantity variances. Labor price variance $ Labor quantity variance $ (c) Compute the labor price and quantity variances, assuming the standard is 4.20 hours of direct labor at $13.50 per hour. Labor price variance $ Labor quantity variance $