Discussion:
Q: An assembly process inlcudes a torque wrench device that automatically tightens compressor housing bolts; the device has a known process standard deviation of o = 3 lb-ft in the torque applied. A simple random sample of 35 nuts is selected, and the average torque to which they have been tightened is 150 lb-ft. What is the 95% confidence interval for the average torque being applied during the assembly process?