Prepare a flexible budget for the SGA expenses at the sales levels provided:

Sales commissions $9\%$ of sales

Ad expense $12\%$ of sales

Miscellaneous expense $$6000$ per month plus $2\%$ of sales

Office expense $$20,000$ per month

Customer support expense $$15,000$ per month plus $5\%$ of sales

$R$&$D$ expense $$30,000$ per month

$$400,000,$$$600,000,$$$800,000$