1. Explain the difference in interpretation between an observation falling below the lower control limit on an X‾ -chart and one falling below the lower control limit on an R-chart. Discuss the impact of each on the revision of control charts in the context of response time to fire alarms.
2. A new hire has been made in a management consulting firm and data are monitored on response time to customer queries. Discuss what the patterns on an X‾- and R-chart might look like as learning on the job takes place.