We know that Richard can apply fertilizer to 4485 square feet = 3/4 hour
To solve this problem, one approach is to find 1/4 then multiply by 4 to get the whole 4/4 or 1 hour.
So the solution would be:
4485/3=1495
Then multiply this by 4.
1495 multiplied by 4 is equal to 5980 square feet.
So Richard can apply fertilizer to 5980 square feet in 1 hour.