Step-by-step explanation:
Margin of error = critical value × standard deviation
We aren't given the critical value or any information to calculate it, so we need to make some assumptions. Assuming the data set is large enough to be approximated as normal, and that the confidence level is 95%, then the critical value is 1.96.
ME = 1.96 × 9.5
ME = 18.62
You may choose to round 1.96 to 2, in which case the margin of error is:
ME = 2 × 9.5
ME = 19
