6. BlueBolt Bottlers has a bottle-filling process with a mean
value of 64 ounces and a standard deviation of 8 ounces.
a. (**) Suppose that the upper and lower tolerance limits
are 71 and 57 ounces, respectively. What is the process
capability ratio? What would the standard deviation
have to be in order for the process to meet the tolerance limits 99.7% of the time?
b. (***) Now suppose BlueBolt Bottlers makes some process improvements, thereby lowering the standard
deviation of the process to 1.5 ounces, rather than
8 ounces. Using the data in problem 10 and the new
standard deviation, calculate the process capability
ratio. Is the filling process able to meet the tolerance
limits 99.7% of the time? Does the process provide Six
Sigma quality levels? Explain.