power plant L offshore facility T Z D ower line is to be run to an offshore facility as shown in the figure above. The offshore facility es at sea and L = 12 miles along the shoreline from the power plant. It costs $ 450 per mile ver line underground and $ 700 per mile to run the line underwater. much of the power line should be run underground, and how much underwater to minimize s? gth underground (in miles): gth underwater (in miles): mal cost (in dollars): help (numbers)