An investor invests $58,000 and receives an annuity of $7,000 at the end of each year for twelve years and an additional payment of $15,000 at the end of the thirteenth year. Each time he gets a $7,000 payment, he immediately deposits $4,000 in a savings account that earns 9%. Find the annual yield received by the investor over the thirteen years.

The answer is 8.43260% but I don't lnow how to formulate the problem. Please do not just use a financial calculator to find the answer, show the necessary steps.