Calculating average operating assets, margin, turnover, and return on investment east mullett manufacturing earned operating income last year as shown in the following income statement: sales $531,250 cost of goods sold 280,000 gross margin $251,250 selling and administrative expense 195,500 operating income $55,750 less: income taxes (@ 40%) 22,300 net income $33,450 at the beginning of the year, the value of operating assets was $390,000. at the end of the year, the value of operating assets was $460,000. required: for east mullett manufacturing, calculate the following: 1. average operating assets $ 2. margin (round to two decimal places) % 3. turnover (round to two decimal places) 4. return on investment (round to one decimal place)