A New Machine Is Set or Calibrated to Fill Tubes

Multiple Choice

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of six tubes is taken every three hours and weighed with the following results: What is the upper control limit (UCL) for the mean?

A) 6.738
B) 6.999
C) 6.777
D) 7.221