1) A barber shop uses process capability to measure the consistency in service times for different customers. The average service time is 30 minutes with a standard deviation of 5 minutes. To meet customer expectations , the service time should be between 25 and 55 minutes (otherwise, they are likely to feel rushed or impatient). Find the process capability ratio Cp. Keep 2 decimal places for your answer.

2)The specification for a plastic liner for concrete highway projects calls for a thickness of 6.0 mm 0.2 mm. The standard deviation of the process is estimated to be 0.02 mm. The process is known to operate at a mean thickness of 6.05 mm. What is the Cpk for this process (round your final answer to two decimal places)?

3)The specification limits for a plastic liner for concrete highway projects calls for a thickness of 6.0 mm 0.1 mm. The standard deviation of the process is estimated to be 0.01 mm. The process is known to operate at a mean thickness of 6.04 mm. What is the Cpk for this process (round your final answer to two decimal places)?