n a random sample of 8 ​people, the mean commute time to work was 33.5 minutes and the standard deviation was 7.4 minutes. A 98​% confidence interval using the​ t-distribution was calculated to be left parenthesis 25.7 comma 41.3 right parenthesis. After researching commute times to​ work, it was found that the population standard deviation is 8.7 minutes. Find the margin of error and construct a 98​% confidence interval using the standard normal distribution with the appropriate calculations for a standard deviation that is known. Compare the results. Question content area bottom Part 1 The margin of error of mu is

enter your response here. ​(Round to two decimal places as​ needed.) Part 2 A 98​% confidence interval using the standard normal distribution is left parenthesis nothing comma nothing right parenthesis .

​(Round to one decimal place as​ needed.) Part 3 Compare the results. Choose the correct answer below. A. The confidence interval found using the standard normal distribution is the same as the confidence interval found using the​ student's t-distribution. B. The confidence interval found using the standard normal distribution is wider than the confidence interval found using the​ student's t-distribution. C. The confidence interval found using the standard normal distribution is narrower than the confidence interval found using the​ student's t-distribution. D. The confidence interval found using the standard normal distribution has smaller lower and upper confidence interval limits.