Discuss specific characteristics that could be monitored through variable control charts, the form of data to collect, and the appropriate control chart in the following situations:
(a) Waiting time to check in baggage at an airport counter
(b) Product assembly time in a hardware company
(c) Time to develop a proposal based on customer solicitation
(d) Emission level of carbon monoxide for a certain model of automobile
(e) Detection of a change in average response time to customer queries when the degree of change is small
(f) Changes in blood pressure of a patient over a period of time
(g) Acceptance of products manufactured in batches, where batch means of the characteristic selected are determined, with the ability to detect a set proportion nonconformance with a desired level of probability
(h) Mortality rate of cardiac surgery patients adjusting for individual patient risk
(i) Time to respond to customer queries received at a call center
(j) Downtime of Internet service provider to individual customers.