The following information is available for Brownstone Products Company for the month of July: Actual Master Budget Units 3,900 3,200 Sales revenue $ 59,500 $ 60,000 Variable manufacturing costs 10,100 16,000 Fixed manufacturing costs 12,000 13,200 Variable selling and administrative expenses 6,600 8,000 Fixed selling and administrative expenses 8,100 9,300 Required: 1. What was the total operating income variance for July? (Note: this variance is also called the master (static) budget variance for the period.) Was this variance favorable (F) or unfavorable (U)? 2. Compute the July sales volume variance and the flexible-budget variance for the month, both in terms of contribution margin and in terms of operating income. 4. Prepare a flexible budget for each of the following two output levels: a. 3,780 units. b. 4,180 units.