An acre is equal to 43,560 square feet, and there are 5280 feet in a mile. If a farm has the shape of a rectangle measuring 0.7 mile by 0.9 mile, what is the area of the farm in acres?
1 acre = 43.560 ft² 5,280 ft = 1 mile Area of the farm: 0.7 miles · 0.9 miles = 3,696 ft · 4,752 ft = 17,563,392 ft² 17,563,392 ft² : 43,560 = 403.2 acres