True/False Indicate whether the statement is true or false. 1. Traditional SPC techniques become ineffective for quality levels approaching six sigma. 2. Statistical process control can detect when to leave a process alone. 3. A histogram of data that resembles the normal distribution indicates that the process is in control. 4. Attribute control charts require larger sample sizes than variable control charts. 5. If a process is neither capable nor in control, steps should first be taken to improve its capability. 6. A process may be capable or not capable, or in control or out of control, independently of each other. 7. If any points on a control chart are determined to be the result of special causes, the points should be eliminated and new control limit values should be computed. 8. In determining whether a process is in statistical control, the R-chart should always be analyzed before the Z-chart. 9. Assignable causes are more difficult to identify in unstable processes. 10. Control limits are the same as specification limits