A dimensional specification of the diameter of Type 1 dowel pin is 1.50 0.02/-0.01 inch. An extrusion process was created to fabricate this type of dowel pin. If a technician randomly picked up 20 fabricated dowel pins and measured their diameters. He got an average value of 1.492 inch with standard deviation 0.002. What is the process capability index(cpk) of this extrusion process