Simple interest is given by the formula A = P + P r t . Where A is the balance of the account after t years, and P is the starting principal invested at an annual percentage rate of r , expressed as a decimal.

Joseph is investing money into a savings account that pays 4% simple interest, and plans to leave it there for 15 years. Determine what Joseph needs to deposit now in order to have a balance of $20,000 in his savings account after 15 years.

Joseph will have to invest $______ now in order to have a balance of $20,000 in his savings account after 15 years. Round your answer to the nearest dollar.