Question

In a random sample of

88

​people, the mean commute time to work was

36.536.5

minutes and the standard deviation was

7.27.2

minutes. A

9898​%

confidence interval using the​ t-distribution was calculated to be

left parenthesis 28.9 comma 44.1 right parenthesis(28.9,44.1).

After researching commute times to​ work, it was found that the population standard deviation is

8.78.7

minutes. Find the margin of error and construct a

9898​%

confidence interval using the standard normal distribution with the appropriate calculations for a standard deviation that is known. Compare the results.

The margin of error of

muμ

is

nothing.

​(Round to two decimal places as​ needed.)

There is two more parts to this question that I cannot view yet.

Answer 1

given data are:-

z critical value for 98% confidence level, both tailed test be:-

the margin of error be:-

the 98% confidence interval be:-

*** if you have any doubt regarding the problem ,please write it in the comment box...if satisfied,please UPVOTE.