# Question

Reconsider the situation described in Exercise 6.1. Suppose that several of the preliminary 20 samples plot out of control on the R chart. Does this have any impact on the reliability of the control limits on the x chart?

## Answer to relevant Questions

An x chart is used to control the mean of a normally distributed quality characteristic. It is known that σ = 6.0 and n = 4. The center line = 200, UCL = 209, and LCL = 191. If the process mean shifts to 188, find the ...Table 6E.15 contains 10 new subgroups of thickness data. Plot this data on the control charts constructed in Exercise 6.26(a). Is the process in statistical control? Control charts on x and R for samples of size n- 5 are to be maintained on the tensile strength in pounds of a yarn. To start the charts, 30 samples were selected, and the mean and range of each computed. This yields (a) ...Consider the chart defined in Exercise 6.48. Find the ARL1 for the chart. Control charts for and R are in use with the following parameters: The sample size is n = 9. Both charts exhibit control. The quality characteristic is normally distributed. (a) What is the a-risk associated with the ...Post your question

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