Problem 15-22 Return on investment LO 15-6 Solomon Corporation's balance sheet indicates that the company has $640,000 invested in operating assets. During 2018, Solomon earned operating income of $81,920 on $1,280,000 of sales. Required ook a. Compute Solomon's profit margin for 2018. b. Compute Solomon's turnover for 2018. c. Compute Solomon's return on investment for 2018. d. Recompute Solomon's ROI under each of the following independent assumptions: (1) Sales increase from $1,280,000 to $1,536,000, thereby resulting in an increase in operating income from $81,920 to $92,160. (2) Sales remain constant, but Solomon reduces expenses, resulting in an increase in operating income from $81,920 to $84,480. (3) Solomon is able to reduce its invested capital from $640,000 to $512,000 without affecting operating income. int ences mplete this question by entering your answers in the tabs below. Req A to C Req D Compute Solomon's profit margin, turnover and return on investment for 2018. (Round "Profit margin" and "Return on investment" to 1 decimal place.) a Profit margin b. Turnover times