Author: Anonymous

A process is in control with  = 40,    =4 and n=5. The three sigma limits for the  chart are:

A process is to be centered at 3.00″. A sample is taken from the process and has a mean of 3.02. Which of the following should be used as a null hypothesis to test whether or not the process is achieving the target mean?

Audit criteria is

A process is in control with control limits established with  = 40,    =4 and n=4. The standard deviation for the process is can be estimated as

Which of the following would not be considered a value-added activity?

A local environmental group is concerned about increasing mineral content near a new manufacturing facility.  Three years ago the silica content in a local river was determined to be 23 mg/L (in the range of 5 to 25 mg/L commonly found in natural waters).  Recently, 6 samples were taken which had an average of 26 mg/L and standard deviation of 1.6 mg/L.  An hypothesis test is to be performed to see if, with a confidence level of 90%, the silica level has increased.  For this hypotheses test, the t critical value which the test statistic should be compared to is

A process is in control with control limits established with  = 40,    =4 and n=4. The standard deviation for the process is can be estimated as

A controlled process has a mean of 50.2 and standard deviation of 0.2. The specification limits for a part on the process are 50±0.8. Cpk for this process is

A sample of size 50 is taken from a population.  The mean of the sample is 41 and standard deviation is 2.9.  What is the 95% confidence interval for the true mean?

If a normality plot for a set of sample data looks like  The associated histogram of the data would look most like