1. To set x-bar chart upper and lower control limits, one must know the process central limit, which is the:
   1. Average of the sample means.
   2. Total number of defects in the population.
   3. Percent defects in the population.
   4. Size of the population.
   5. Average range.
   6. None of the above
2. General Electric (GE) is a Six Sigma company, what does Six Sigma mean here?

a) GEs production process is under control.

b) GEs production process produces at most 99.97% good quality products.

c) GE prevents the process from producing more than 0.000002% bad quality product

d) All of the above

e) None of the above

3. In a given X-bar chart the difference between 3-sigma UCL and LCL is 18 and A2=0.419. What is n?

a) 6

b) 3

c) 7

d) 12

e) Need more information