The specification for a plastic handle calls for a length of 6.0 inches 0.3 inches (5.7 to 6.3 inches). The process is known to operate at a mean thickness of 5.9 inches. The minimum acceptable process capability is 4-sigma (1.33). The standard deviation () of the process is currently 0.07 inches.

c) The specification limits have not changed.Suppose that the mean of the process is still 5.95 inches with a standard deviation () of 0.06. What is the range (upper and lower limits) on the mean of the process to maintain a C_pk of 1.33 or greater?

d) Suppose that the mean of the process is now operating at a mean of 6.05 inches but the standard deviation has worsened and is now 0.12 inches and the process follows a normal probability distribution. The lower spec (specification) limit is still 5.70 and the upper spec limit is still 6.30. What percent of the values are above the upper spec limit?