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A power line is to be constructed from a power station at point A to an island at point C, which is 3 mi directly out in the water from a point B on the shore. Point B is 4 mi downshore from the power station at A. It costs $2800 per mile to lay the power line under water and $2000 per mile to lay the line under ground. At what point S downshore from A should the line come to the shore in order to minimize cost? Note that S could very well be B or A. (Hint: The length of CS is 19+ x2.) EX 4-X S is miles from A. (Round to two decimal places as needed.)