Final answer:
To find out how far the plane can fly in 7 hours, we calculate the speed at 70 miles per hour based on the information provided and then multiply this by 7, determining the plane can fly 490 miles.
Step-by-step explanation:
If a plane can fly 280 miles in 4 hours, we can calculate the plane's speed by dividing the distance by the time. This gives us a speed of 280 miles / 4 hours = 70 miles per hour. To find out how far the plane could fly in 7 hours at this rate, we simply need to multiply the speed by the time: 70 miles/hour × 7 hours = 490 miles. So, the plane could fly 490 miles in 7 hours at the given rate.