Question 1
An x-bar control chart was examined and no data points fell outside of the limits. Can this process be considered in control?
◦ No, the number of samples must be known.
◦ Yes.
◦ Yes, there is not enough data to determine otherwise.
◦ No, there could be a pattern to the points, the R-chart must be checked.
◦ Yes, it is unlikely that there is a pattern in these points.
Question 2
Statistical process control charts
◦ display the measurements on every item being produced.
◦ display upper and lower limits for process variables or attributes, and signal when a process is no longer in control.
◦ indicate to the process operator the average outgoing quality of each lot.
◦ display the measurements on every item being purchased.
◦ indicate to the operator the true quality of material leaving the process.