Prepare a manufactoring overhead budget . duncan compnay combines its operating expenses for budget purposes in a selling and administrative expense budget. for the first 6 months of 2012 the following data are available 1. sales: 20,000 units quarter 1:22,000 units quarter 2 2. variable costs per dollar of sales : Sales commissions 5% deliver expense 2% and advertising 3% 3.fixed cost per quarter sales salaries $10,000, office salaries $6,000. depreciation $4200 inusarce $1500 utitltes $800 and reparis expense $600 4, unit selling price $20