A new food delivery robot on a college campus is doing test runs at a constant speed of 4 miles per hour. The average test run is 3 miles from the campus cafeteria but varies a distance of 1.5 miles more or less than that. If x is the number of hours the robot is performing a test run, the equation that can be used to find the minimum and maximum time (in hours) for a test run is ( ) . For each test run, the minimum time is ( )hours and the maximum time is ( ) hours.