Final answer:
Fred ran at a speed of 5 miles per hour. At this speed, it would take him 1.7 hours to run 8.5 miles.
Step-by-step explanation:
Fred is training for a cross-country race and ran 6.25 miles in 1 1/4 hours. To find out how long it would take Fred to run 8.5 miles at the same speed, we first calculate his speed during practice. Fred's speed is 6.25 miles / 1.25 hours = 5 miles per hour. Next, we can calculate the time it would take to run 8.5 miles at this speed by dividing the distance by the speed: 8.5 miles / 5 miles per hour = 1.7 hours.
Therefore, at the speed of 5 miles per hour, it would take Fred 1.7 hours to run 8.5 miles.