An island is 9 mi from the nearest point on a straight shoreline; that point is 16 mi from a power station (see figure). A Utility company plans to lay electrical cable underwater from the island to the shore and then underground along the shore to the power station. Assume that is costs $1600/mi to lay cable underwater and $800/mi to lay underground cable. At what point should the underwater cable meet the shore to minimize the cost of the project?