Calculating average operating assets, margin, turnover, and return on investment barnard manufacturing earned operating income last year as shown in the following income statement: sales $4,000,000 cost of goods sold 2,100,000 gross margin $1,900,000 selling and administrative expense 1,100,000 operating income $ 800,000 less: income taxes (@ 40%) 320,000 net income $480,000 at the beginning of the year, the value of operating assets was $2,700,000. at the end of the year, the value of operating assets was $2,300,000. required: for barnard manufacturing, calculate: 1. average operating assets $ 2. margin % 3. turnover 4. return on investment