Final answer:
The margin of error can be calculated by subtracting the lower bound of the confidence interval from the mean and then dividing the result by 2. The margin of error in this case is 4.55.
Step-by-step explanation:
The margin of error can be calculated by subtracting the lower bound of the confidence interval from the mean and then dividing the result by 2.
In this case, the mean is 52.9 and the lower bound is 43.8, so the margin of error is (52.9 - 43.8) / 2 = 4.55.
Therefore, the correct answer is (d) 4.55.