Suppose that a real estate agency makes its money by taking a
percentage commission of total sales. It also has fixed costs of $15,257 per month associated with rent, staff salaries, utilities, and supplies. In the month of August, total sales were $832,000 and net income (after paying fixed costs) was $9703. Because each dollar increase in sales results in the same increase (a certain percentage of that dollar) in net income, net income is a linear function of total sales. Find a linear formula that gives net income in terms of total sales. What percentage commission on sales is this company charging?