Branch Corp. uses a standard cost system to account for the costs of its one product. Variable overhead is applied using direct labor hours. Standards allowed for each unit are 29 hours of labor at a variable overhead rate of $11. During November, Branch Corp. produced 2,200 units. Payroll totaled $97720 for 7100 hours worked. Variable overhead incurred totaled $79,960. a. Calculate the variable overhead 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 A b. Calculate the variable overhead efficiency variance. (Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance).) Emiciency Variance