Required Compute variances for the following items and indicate whether each variance is favorable (F) or unfavorable (U): (Select "None" if there is no effect (i.e., zero variance).) Item Budget Actual Variance Effect Sales price $ 668 $ 534 Sales revenue 589,000 618,000 Cost of goods sold 398,500 369,000 Material purchases at 5,000 pounds $ 284,000 $ 293,500 Materials usage 193,500 187,000 Production volume 1,040 units 945 units units Wages at 4,000 hours 61,800 69 59,600 Labor usage at $16 per hour 96,900 98,800 Research and development expense 31,000 38,500 Selling and administrative expenses 62,500 $ 49,000