Studies on a machine that molds plastic water pipe indicate that when it is injecting 29.98 mm diameter pipe, the process standard deviation is 0.81 mm. The pipe has a specification of 29.98 mm plus...

Studies on a machine that molds plastic water pipe indicate that when it is injecting 29.98 mm diameter pipe, the process standard deviation is 0.81 mm. The pipe has a specification of 29.98 mm plus or minus 1.81 mm. What is the process capability index (Cp)?