I need help solving this general accounting question with the proper methodology.

Evergreen Corporation is considerimg investing $12 million immediately in a 4 year capital project. They have calculated the annual profit after tax (and loss after tax in year 3), and the annual cash flows after tax as follows: e Year 1: Profit $4.5m - Cash flow at year end $7m * Year 2: Profit $2.2m - Cash flow at year end $4.7m e Year 3: Loss ($1.5m) - Cash flow at year end $0.5m e Year 4: Profit $3.8m - Cash flow at year end $5.8m ADDITIONAL INFORMATION: Residual value at the end of year four is estimated to be $2 million. Evergreen Corporation has a cost of capital of 15% p.a. Calculate the Accounting Rate of Return on Average Investment