Your engineering firm is bidding for the contract to construct the tunnel shown on the next page

Your engineering firm is bidding for the contract to construct the tunnel shown on the next page. The tunnel is 300 ft long and 50 ft wide at the base. The cross section is shaped like one arch of the curve y = 25 cos (πx/50). Upon completion, the tunnel’s inside surface (excluding the roadway) will be treated with a waterproof sealer that costs $1.75 per square foot to apply. How much will it cost to apply the sealer?