Wharton Tooling uses a standard cost system to account for the costs of its one product. Standard labor input is 14 hours per unit. The standard variable overhead rate is $9.00 per direct labor hour, and fixed overhead is budgeted at $150 per unit, based on budgeted production of 650 units. During July, Wharton Tooling produced 600 units. Payroll totaled $112,930 for 8,770 hours worked. Overhead incurred was $78,053 variable and $98,750 fixed. Required: a. Caiculate the variable overhead rate variance. Note: Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance). b. Calculate the variable overhead efficiency variance. Note: Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance). c. Calculate the fixed overhead spending variance. Note: Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance)