A Proctor and Gamble Factory Process Fills Boxes with Detergent

Multiple Choice

A Proctor and Gamble factory process fills boxes with detergent. Construct an appropriate set of control charts to monitor the process. Historical data for fill weight (in ounces) of eight samples is presented below. A sample size of six was used.
$\begin{array} { c c c } \text { Sample } & \text { Sample Mean } & \text { Sample Range } \\\hline 1 & 15.80 & 0.42 \\2 & 16.10 & 0.38 \\3 & 16.02 & 0.08 \\4 & 15.95 & 0.15 \\5 & 16.12 & 0.42 \\6 & 16.18 & 0.23 \\7 & 15.87 & 0.36 \\8 & 16.20 & 0.40\end{array}$ Worksheet (this will not be graded but will help you answer exam questions)

-For the Proctor and Gamble detergent box problem, based on the control charts it can be said that _____.

A) both the R- and X-bar charts are not in statistical control
B) the R-chart is not in statistical control, but the X-bar chart is in statistical control
C) the R-chart is not in statistical control, but the X-bar chart is in statistical control, and therefore, the process should be stopped and sources of error investigated
D) the R-chart is in statistical control, but the X-bar chart is not in statistical control, and therefore, the process should be stopped and sources of error investigated