Na 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 2.9 hours of labor at a variable overhead rate of $11. During November, Branch Corp. produced 2,250 units. Payroll totaled $97,750 for 7,130 hours worked. Variable overhead incurred totaled $81,080 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 fi.e., zero variance).) Rate Variance 123 Favorable None Unfavorable b. Calculate the variable overhead efficiency variance. (Indicate the effect of variance by selecting "Favorable", "Unfavorable". or "None" for no effectie, zero variance))