The following information is available for Brownstone Products Company for the month of July: Required: 1. What was the master budget variance for July? Was this variance favorable or unfavorable? 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 pro-forma budgets for activities within its relevant range of operations. Prepare a flexible budget for each of the following two output levels: a. 3,930 units. b. 4,330 units