Boston Tooling uses a standard cost system to account for the costs of its one product. Standards are 4.0 sheets of inch steel at $110 per sheet and 14.1 hours of labor at a standard wage rate of $13. During July, Boston Tooling produced 620 units. Materials purchased and used totaled 2,580 sheets at a total cost of $272,600. Actual direct labor cost totaled $113,040 for 8,790 hours worked. a. Calculate the direct materials price variance. (Do not round your intermediate calculations. Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance).) Price Variance b. Calculate the direct materials quantity variance. (Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance).) Quantity Variance c. Calculate the direct labor rate variance. (Do not round your intermediate calculations. Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance).) Rate Variance d. Calculate the direct labor efficiency variance. (Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance).) Efficiency Variance