Please help to solve the question 6.42 The answer for this question is cpk=1.125 Please give me the detailed explanation of this question and answer.Thank you so much

56.42 Linda Boardman, Inc., an equipment manufacturer in Boston, has submitted a sample cutoff valve to improve your manufacturing process. Your process engineering department has conducted experiments and found that the valve has a mean (u) of 8.00 and a standard deviation (o) of .04. Your desired perfor- mance is p = 8.0 30, where o = .045. What is the Cpk of the Boardman valve? PX