Write the definition of a function named timeonhighway that receives three parameters, all of type double: mileendingpoint , milestartingpoint , and speed . the first two parameters indicate the mile markers on an interstate at which a vehicle goes to and starts at; the third parameter indicates the speed of the vehicle in miles per hour. the function returns the number of hours it takes a vehicle to go from the starting mile marker to the ending one. the function has a default value for the speed: 55 miles per hour, and a default value for milestartingpoint : 0.0.