In 2011 the U.S. Department of Transportation reported with 95% confidence that the average length of a motor vehicle trip in the United States was 9.72 miles with a margin or error of 0.22 miles.

Question

With 95% confidence the authors of the report are claiming that the true average length of a motor vehicle trip in the United States is between 

_________ and _________ miles

The level of confidence for this estimate is __________%

Answer 1

ME = 0.22 miles and X-bar = 9.72 miles.

The 95% CI is X-bar -/+ ME = (9.50, 9.94) miles.

The level of confidence is 95% (This is given as part of the problem)