Naomi Matthews
Role of IET
Exam #1
Question #3
Throughout the production process in a Coca-Cola bottling plant, quality control
engineers monitor the product and analyze test samples at the end of the production line. For
example, an important variable that would be inspected for quality standards would be the
volume of liquid in each bottle. Since it would be impractical to inspect every single bottle that
is manufactured, a sample of data would be collected to represent the population of data. Since
a high volume of bottles are filled daily
1
, relatively large samples would be most effective in
calculating data dispersion. Therefore, the X-bar (average) and s (standard deviation) charts
should be used since they are most ideal for a high volume of production.
2
The X-bar control chart indicates where the process is centered, and the s chart shows
how much variability is typical in the process. Each show reasonable limits for the average (x-
bar chart) and standard deviation (s chart). These charts would be useful to the Coca Cola
quality control engineer if he wanted to measure the stability of the bottle filling system. If any
