QuestionIn a random sample of 8 people, the mean commute time to work was 34.5 minutes and the standard deviation was 7.2 minutes. A $95 \%$ confidence interval using the $t$-distribution was calculated to be ( 28.5 .40 .5 ). After researching commute times to work, it was found that the population standard deviation is 9.3 minutes. Find the margin of error and construct a $95 \%$ confidence interval using the standard nomal distribution with the appropriate calculations for a standard deviation that is known. Compare the results.
The margin of error of $\mu$ is $\square$ (Round to two decimal places as needed.)