Statistics

  1. Does the OTR time appear to be stable? Why or why not?
    Create a Moving Range Control Chart for each country code to answer the question. Copy and paste the
    graphs only for the country codes that are not stable.
  2. If you were to use a control chart to evaluate stability, which chart would you use? Why?
  3. What can you learn about the distribution of the installation process?
  4. Does it appear that the country has an impact on installation time? Why or why not?

Sample Solution