Each day for two workweeks (10 days total), George weighs 4 bags from that day’s production. If the average of the means is 14 oz. and the average range is 0.4 oz., what is the lower control limit for an x-bar chart for this process?
a. 13.7084 oz.
b. 13.8768 oz.
c. 14.2916 oz.
d. 12.8000 oz.
e. 13.5908 oz.