Using samples of 194 credit card statements, an auditor found the following:
Sample: 1 2 3 4
Number with errors: 4 6 5 8
c. What is your estimate of the mean and standard deviation of the sampling distribution of fractions defective for samples of this size? (Round your intermediate calculations and final answers to 4 decimal places.)
Mean:_____
Standard deviation: _____
d. What control limits would give an alpha risk of .03 for this process? (Round your intermediate calculations to 4 decimal places. Round your "z" value to 2 decimal places and other answers to 4 decimal places.)
Z:_____
Lower limit:_____
Upper limit:_____
e. What alpha risk would control limits of .0122 and .0470 provide? (Round your intermediate calculations to 4 decimal places. Round your "z" value to 2 decimal places and "alpha risk" value to 4 decimal places.)
z =
alpha risk =
f. Using control limits of .0122 and .0470, is the process in control? Explain why.
yes or no
g. Suppose that the long-term fraction defective of the process is known to be 2 percent. What are the values of the mean and standard deviation of the sampling distribution? (Round your intermediate calculations and final answers to 2 decimal places.)
Mean:_____
Standard deviation: _____
h.Construct a control chart for the process, assuming a fraction defective of 2 percent, using two-sigma control limits. Is the process in control? Explain why.
Yes or No
Quick Reply
