A company making tires for bikes is concerned about the exactwidth of their cyclocross tires. The company has a lowerspecification limit of 22.6 mm and an upper specification limit of23 mm. The standard deviation is 0.14 mm and the mean is 22.8 mm.(Round your answer to 4 decimal places.) What is the processcapability index for the process?
Expert Answer
Lower specification limit, LSL = 22.6 mm
Upper specification limit, USL = 23 mm
Process mean, m = 22.8 mm
Standard deviation, s = 0.14 mm
Process capability index, Cpk = MIN( (USL-m)3s, (m-LSL)/3s)
= MIN( (23-22.8)/(3*0.14), (22.8-22.6)/(3*0.14))
= MIN( 0.4762, 0.4762)
= 0.4762