The specifications for a plastic liner for concrete highway

The specifications for a plastic liner for concrete highway projects calls for a thickness of 3.0 mm ±.1 mm. The standard deviation of the process is estimated to be .02 mm. What are the upper and lower specification limits for this product? The process is known to operate at a mean thickness of 3.0 mm. What is the Cpk for this process? About what percentage of all units of this liner will meet specifications?