Consider the capability of a process that puts pressurized grease in an aerosol can. The design specs call for an average of 60 pounds per square inch (psi) of pressure in each can with an upper tolerance limit of 67psi and a lower tolerance limit of 56psi. A sample is taken from production and it is found that the cans average 61psi with a standard deviation of 2psi.

What is the Cpk(3sigma) of the process?