Producers of a particular brand of ready-to-eat breakfast cereal place, in theory, 15 ounces of cereal in each box of this product. In an effort to assess this stage of the manufacturing process, an operations manager gathers 25 subsamples of 4 observations each on the amount (measured in ounces) of cereal in selected boxes. These data are given in the file P20_05.xlsx.

a. Generate and interpret X and R charts for the given data. Does this process appear to be in control?

b. Are there any other indications that the given process may be out of control? If so, explain.

c. If your analysis reveals that a problem does exist with the process, what advice would you give to the manager of this operation?