A Statistic Q Is to Be Used to Monitor a Process

question 77

Multiple Choice

A statistic Q is to be used to monitor a process over time,using a control chart for that statistic.When the process is running in a state of control,it is known that the statistic Q has mean and standard deviation
.Which of the following is NOT a feature of the appropriate three-sigma control chart for Q?

• A)Values of Q,obtained from regular samples from the process,will be plotted on the control chart against the time order of the samples.
• B)A signal will be given if the value of the statistic Q falls between the upper control limit (UC
• L)and the lower control limit (LC
• L).
• C)The center line for the control chart will be set at .
• D)The lower control limit (LC
• L)will be set at - 3 .
• E)The upper control limit (UC
• L)will be set at + 3 .