Question 8.160

commutedist

63. Commuting Distances. A university is trying to attract more commuting students from the local community. As part of the research into the modes of transportation students use to commute to the university, a survey was conducted asking how far commuting students commuted from home to school each day. A random sample of 30 students provided the distances (in miles) shown.

14 10 14 12 12 11 5 6 9 14 9 9 4 7 15
9 7 7 12 10 15 10 6 11 9 11 10 11 7 12
  1. Find for a confidence interval with 90% confidence.
  2. Compute and interpret the margin of error for a confidence interval with 90% confidence.
  3. Construct and interpret a 90% confidence interval for the population mean commuting distance.

8.2.63

(a) (b) mile. We can estimate the population mean commuting distance to within 0.9 mile with 90% confidence. (c) (9.0, 10.8). We are 90% confident that μ, the population mean commuting distance, lies between 9.0 miles and 10.8 miles.