Question

In a random sample of 8 ​people, the mean commute time to work was 35.5 minutes and the standard deviation was 7.4 minutes. A 98​% confidence interval using the​ t-distribution was calculated to be left (27.7,43.3).

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.

Margin of Error of u is ________

Answer 1

Note-when population sd is given..we will use z statistic....if there is any understanding problem regarding this please feel free to ask via comment box..thank you