Problem 17-36 Variable Cost Variances: Materials Purchased and Used Are Not Equal (LO 17-1, 6) Griffen Company makes pipe using metal. The company uses a standard costing system. Variable overhead is allocated on the basis of direct material usage (pounds). Overhead is allocated to units based on expected production of 13,400 units. Griffen maintains a materials inventory, so the amount of material used is not necessarilly the same as the amount of material purchased in any one month. The standard cost sheet for a unit of pipe follows: Direct material Direct labor Variable overhead Fixed ovwerhead 9 pounds S8 72.00 5 hours $28 140.00 9 pounds 45.00 23.00 $280.00 August financial results show that the average purchase price of metal was $8.30 per pound. The purchase price variance $35,400 unfavorable. The variable overhead efficiency variance was 9,400 unfavorable. Good output produced totaled 16,400 units. Required: a. How many pounds of metal were purchased in August? (Do not round intermediate calculations.) Metals purchased pounds b. What was the direct material efficiency vanance in August? (Do not round intermediate calculations. Indicate the effect of each variance by selecting "F" for favorable, or "U" for unfavorable. If there is no effect, do not select either option.) Efficiency variance c. How many pounds of metal were used in August? (Do not round intermediate calculations.) Metals used pourds