Studies on a machine that molds plastic water pipe indicate that when it is injecting 25 mm diameter pipe,the process standard deviation is 0.50 mm.The 25 mm pipe has a specification of 25 mm plus or minus 1.0 mm.What is the process capability index (Cp)?
A) 0.50
B) 0.67
C) 1.00
D) 2.00
E) None of the choices are correct.

Question

Quizplus · Accepted Answer

The process capability index (Cp) can be calculated using the formula: Cp = (USL-LSL)/(6*sigma), where USL is the upper specification limit, LSL is the lower specification limit (in this case, the lower limit is not given, so we assume it to be 24 mm), and sigma is the process standard deviation.

Using these values, Cp = (26-24)/(6*0.50) = 0.67

Therefore, the answer is B) 0.67.

Studies on a Machine That Molds Plastic Water Pipe Indicate