Flexible budget for selling and administrative expenses for a service company Digital Solutions Inc. uses flexible budgets that are based on the following data: Sales commissions Advertising expense Miscellaneous administrative expense Office salaries expense Customer support expenses Research and development expense 14% of sales 20% of sales $7,500 per month plus 12% of sales $30,000 per month $12,000 per month plus 20% of sales $31,000 per month. Prepare a flexible selling and administrative expenses budget for October for sales volumes of $400,000, $500,000, and $600,000. (Use Exhibit 4 as a model.)