Answer: Correct, 4.4 is the answer when rounded, but to be more exact, it would be 4.420
Explanation:
The only discrepancy is the rounding, the rest of the work is correct. It is subjective to the teacher whether the answer is sufficient or not, but you did a great job otherwise. If your teacher does want preciseness, however, I would not round to 4.5, it would be more accurate as 4.44 when setting up your equation.