How many feet are equal to 4840 square yards?
You need one more piece of information. One other dimension (if a rectangular area), in feet, of the area you are using/measuring. Take "the other dimension in feet" and divide it by 9. Assuming your other dimension is 12 feet, 12/9 = 1.333333, therefore in your case do this 4840/1.333333 = 3630 lineal feet. Warning, this only works on rectangular areas.