how did they get this answer?

Roberts Hardware is adding a new product line that will require an investment of $1,512,000. Managers estimate that this investment will have a 10 -ye generate net cash inflows of $300,000 the first year, $280,000 the second year, and $240,000 each year thereafter for eight years. Assume the project value. Compute the ARR for the investment. Round to two places. Select the formula, then enter the amounts to calculate the ARR (accounting rate of return) for the new product line. (Round ARR to the nearest hundred decimal places], XXX\%.)