Which of the Following Statements Are True

Multiple Choice

Which of the following statements are true?

A) We might think of "natural random variation" as uncontrollable background noise.
B) Control charts provide a mechanism for recognizing situations where assignable causes may be adversely affecting product quality.
C) Once a control chart indicates an out-of-control situation, an investigation can be launched to identify causes and take corrective action.
D) A basic element of control charting is that samples have been selected from the process of interest at a sequence of time points.
E) All of the above statements are true.