Confidence Interval Analysis –


For this assignment, you will apply your understanding of confidence intervals in statistics. You should use these answers in project presentation during Week 7, so this week continues to scaffold the process of the final project. Please refer back to your chosen research question from Week 1 and the associated data set that you gathered in Week 2.

Activity Instructions

  • After briefly describing the nature of the data set, showing your step-by-step work for each question:
  • Please determine the 90%, 95%, and 99% confidence intervals, assuming that sigma is unknown, list each in proper (lower bound, upper bound) notation
  • Which has the smallest range?
  • Why do you think that is?
  • What would be the effect on the original 95% confidence interval if the sample size were increased by 10 data points?
  • How would the original 95% confidence interval be affected if the standard deviation were doubled?

Writing Requirements (APA format)
Download and fill in template (see example for help)

  • 2 paragraphs
  • 1-inch margins
  • Double spaced
  • 12-point Times New Roman font
  • References page