Question

a used car dealer wants to know the mean mileage of the cars currently in his lot. Rather than checking all of the cars, he samples 25 cars and finds that the mean mileage of the sample is 12,456.25. Assuming a standard deviation of 225 miles a confidence level of 95%, what is the margin of error for the sample mean? Use z=1.960

answers-
17.64
52.6
88.2
104.67

Thanks for the help in advance