A sample of 25 commuters in a certain city is selected and the distance that each computer takes from home to work is recorded, yielding a sample mean, x= 21.6 km and a sample standard deviation, s= 4.3km. Let denote the overall mean home-to-work travel distance for commuters in this city.

What would the 90% confidence interval for be and what is the value of the standard error in the confidence interval?

If we constructed an additional confidence interval for using the same data but now with a confidence level, C that isgreater than 90%what would be the effect on the margin of error of the confidence interval?