Variable control chart

For any process, the sample ranges are, 1.2,1.5,1.1,1.4,1.5. The subgroup size is 5. What will be the process standard deviation? Given: d2=2.326 and A2=0.577

• 0.576

• 2.322

• 0.511

• 2.463

The natural variability of the process is measured by ____

• Process mean

• Sample standard deviation

• Process standard deviation

• Sample mean

Natural variations are the many sources of variation within a process that

• are not perfect.

• have several assignable causes of variation.

• are out of control.

• are in statistical control.

• none of the above

Using the terminology of statistical control, the variation within a stable system

• is random variation

• results from common causes.

• is predictable within a range.

• a and b.

• all of the above.

Using the terminology of statistical control, the variation outside the control limits on an X-bar or range chart

• is viewed as uncontrollable.

• is assumed to have been caused by special or assignable causes.

• indicates that the system is probably out of control.

• indicates that the system is out of control by special causes

• all of the above.

Calculate CL of X chart? (1 decimal, ex: 5.2 or 8.9)

Calculate X chart:

UCL = ? ( 2 decimal, ex: 20.91 or 57.92)

Calculate X chart:

LCL = ? ( 2 decimal, ex: 20.91 or 57.92)

Calculate R chart:

CL = ? (1 decimal, ex: 23.4 or 22.2)

Calculate R chart:

UCL = ? (1 decimal, ex: 23.4 or 22.2)