4 miles 2560 feet = 7893 yards and 1 foot
1 mile = 1760 yards, so 4 miles = 7040 yards
1 foot = 1/3 of a mile, so 2560 feet = 853 yards and 1 foot left over
So to get your final answer add 7040 yards to 853 yards and 1 foot and you get 7893 yards and 1 foot