The following table shows the risk class of six projects and the IRR estimates. The projects are grouped in five risk categories: Highest Risk, High Risk, Average Risk, Low Risk and Lowest Risk. The firm's WACC is 18 per cent. The firm has a policy of adding 4 per cent to WACC for the above risk projects, another 4 per cent for the highest risk projects. Similarly, the firm deducts 4 percent from the WACC for low risk projects and another 4 percent for the lowest risk projects