Problem 4 (40 points) One stone bridge is to be built at a labor and material cost of $32.000. Maintenance is required at the end of every five years for a cost of $460 (each time). The interest rate is 6.5%, compounded monthly. Assume that the lifetime of the bridge is 80 years, When the lifetime of the bridge is reached, no maintenance is required. What is the present cost of the bridge