BHC produces bags of cement. The stated weight for a bag of cement is 100 lbs. Customers will accept an occa- sional bag weighing as little as 96 lbs. as long as the average weight is at least 100 lbs. At the same time, BHC doesn't want to give away cement, so it has set an upper tolerance limit of 104 lbs. The current filling process has an actual process mean of 101 lbs. and a standard devia- tion of 0.65 lb.
a. Calculate the process capability index for BHC. In this example, why should we use the process capability index, rather than the process capability ratio, to assess capability?
b. Can you think of any reason why BHC might want a process mean higher than the target value?