Which of the following statements about standard costs is false? Properly set standards should promote efficiency. Standard costs can simplify the costing of inventories. Standards should not be used in "management by exception." Standard costs facilitate management planning. When is a variance considered to be significant? When it is large compared to the actual cost When it is unfavorable When it is infrequent When it could have been controlled more effectively If actual costs are greater than standard costs, there is a(n) error in the accounting system. normal variance. favorable variance. unfavorable variance. The total materials variance is equal to the sum of the materials price variance and the materials quantity variance. difference between the materials price variance and materials quantity variance. product of the materials price variance and the materials quantity variance. materials price variance