Answer:
The correct answer is that Charlie made a guess with a 5.2% error.
Explanation:
We have that a % error could be written as

where approx is the estimate value that Charlie made, exact is the actual weight of the dog, and approx minus exact should be expressed in absolute value.
Doing this calculation, we have that

and taking the result to the nearest tenth of a percent, we actually have the correct answer, wich is 5.2%.