First, you need to find the range of possible estimates, you can find this by multiplying 0.15 by 48 which equals 7.2, this means that the estimates have to be less than 7.2 pounds away from 48.
The lowest possible estimate is 48 - 7.2 which equals 40.8 and the highest possible estimate is 48 + 7.2 which equals 55.2.
If it is in between 40.8 and 55.2, then it's a possible estimate, if not, not possible.