18. C&As potato chip filling process has a lower specification limit of 10.5 oz. and an upper specification limit of 11.5 oz. The standard deviation is 0.15 oz. and the mean is 11 oz. What is the process capability index for the chip filling process?

A. 1.77 B. 0.56 C. 3.33 D. 1.11

19. An X-bar chart has _______ on the x-axis and _______ on the y-axis.

A. samples, sample variations B. time periods at which samples are taken, sample variations C. samples, sample means D. time periods at which samples are taken, sample means