Question

Operation of the fill process, 22 subgroups of five bag fills are observed. Using the observed data, X bar and R bar are calculated to be 52.9364 pounds and 1.6818 pounds, respectively. When the 22 bars and 22 R’s are plotted with respect to the appropriate control limits, the first 6 subgroups are found to be out of control. This is traced to a mechanical start-up problem, which is remedied. Using the remaining 16 subgroups, and X bar and R bar are are calculated to be 52.5875 pounds and 1.2937 pounds, respectively. Calculate appropriate revised X bar and R chart control limits. When the remaining 16 X bars’ and 16 R’s are plotted with respect to the appropriate revised control limits, they are found to be within these limits. What does this imply?

Answer 1

B)

If remaining 16 points inside the LCL and UCL, then the process has no out of control points.

So this process is in statistical control.