Originally Posted by

**jenniferz3** I am attempting to do this question, but every time I look at it, I just get more confused. I have no idea how to even start. I'm especially confused about how to show the relationship between the values. Please help =/

**The cost of fuel (dollars/hour) to propel a ferry boat through water is proportional to the cube of the speed of the ferry boat.** A certain ferry boat uses $100 of fuel per hour when cruising at 10 miles per hour. Apart from fuel, the operational cost of running the ferry is $675 per hour. At what speed should the ferry boat cruise at to minimize the cost per mile traveled?