Control chart limits for a measured characteristic have been calculated as follows (assume a sample size of n = 5):

X-bar chart: R chart:

UCL = 218.46 UCL = 12.7

CL = 215 CL = 6

LCL = 211.53 LCL = 0

Suppose a sample has been drawn consisting of the following observations:

215 218 216 208 223

If we base our conclusions solely on the information in this sample;

2) Which of the following statements is true based on this process?

1. This process is an IN-CONTROL process
2. This process is an OUT-OF-CONTROL process because X-bar chart is OUT-OF-CONTROL
3. There is not enough information to decide IN-CONTROL or OUT-OF-CONTROL
4. This process is an IN-CONTROL process because X-bar chart is IN-CONTROL
5. This process is an IN-CONTROL process because R-chart is IN-CONTROL
6. None of the above (What is your answer?)

3) Which of the following statements about the CAPABILITY of this process is true if the process standard deviation is 3.355 and specifications are at 216 5?

1. This process is a CAPABLE process because Cp is more than 1.
2. This process is a CAPABLE process because Cpk is more than 1.
3. This process is an INCAPABLE process because Cp is less than 1.
4. This process is an INCAPABLE process because Cpk is less than 1.
5. There is not enough information to decide CAPABLE or INCAPABLE.
6. None of the above (What is your answer?)

4) Which of the following statements about the CAPABILITY of this process is true if the process standard deviation is unknown and specifications are at 216 5?

1. This process is a CAPABLE process because Cp is more than 1.
2. This process is a CAPABLE process because Cpk is more than 1.
3. This process is an INCAPABLE process because Cp is less than 1.
4. This process is an INCAPABLE process because Cpk is less than 1.
5. There is not enough information to decide CAPABLE or INCAPABLE.
6. None of the above (What is your answer?)