A simple random sample of 62 colleges and universities in the United State had a mean tuition of 18 974 with a standard deviation of 9 640 a Construct a 89 confidence interval for the mean tuition for all colleges and universities in the United States Please round the answers to 3 decimal places Critical value z or t Margin of Error E Confidence Interval Enter the positive one b Interpret your result in part a in a complete sentence