The UCL and LCL for an Chart Are 25

question 21

Multiple Choice

The UCL and LCL for an chart are 25 and 15 respectively.The central line is 20,and the process variability is considered to be in statistical control.The results of the next six sample means are 18,23,17,21,24,and 16.What should you do?

• A)Nothing;the process is in control.
• B)Explore the assignable causes because the second,fourth,and fifth samples are above the mean.
• C)Explore the assignable causes because there is a run.
• D)Explore the assignable causes because there is a trend.

---

Definitions:

Sample

A subset of individuals or observations drawn from a population used for statistical analysis, intended to represent the population from which it is drawn.

Population

The entire group of individuals or instances about whom the study is to make inferences, in contrast to a sample drawn from it for analysis.

Census

A systematic collection, analysis, and publication of data pertaining to the population and its components at a specific time.

Anecdotal Evidence

Evidence based on personal accounts or individual instances rather than systematic scientific research.