Which of the following statements concerning performance evaluation tools used in decentralized operations iscorrect? Performance reports can only be used to evaluate the performance of cost centers. Segment margin is calculated by subtracting the common fixed costs allocated to a segment from the segment's contribution margin. A positive residual income indicates that a segment's retura on investment is greater than the company's. target rate of return. A segment's return on investment can be calculated by dividing the segment's sales margin percentage by its capital turnover ratio. Segmented income statements are also referred to as budget versus actual reports