Chapter 13: Control Charts and Sampling Strategy

The process mean and sample mean are the same. - ANS FALSE Two samples from the same population and taken at the same point in time are likely to have the same sample mean. - ANS FALSE A line chart is constructed from a scatter plot. - ANS TRUE A control chart must have an UCL and LCL but it is not necessary to have a centerline or target. - ANS FALSE Both an LCL and UCL must be included in every control chart. There are no exceptions. - ANS FALSE A stable process is one where all causes of variation are known. All steps and activities within the process are centered at their target values and variation is consistent with output objectives. - ANS TRUE If the LCL and UCL are positioned plus and minus two standard errors of the mean from the mean of the distribution of samples means, the likelihood that a sample result will fall outside these limits is _____ percent. - ANS 5 When a sample falls outside the UCL but the process is still in-control this would be considered a Beta error. - ANS FALSE A Beta error occurs when the process mean has shifted but a sample mean from the process still occurs within the UCL and LCL limits. - ANS TRUE