A machine at K-Company fills boxes with bran flakes cereal. The target weight for the filled boxes is 24 ounces .The company would like to use an -chart to monitor the performance of the machine. To develop the control chart, the company decides to sample and weigh five consecutive boxes of cereal five times each day (at 8:00 and 11:00 A.M. and 2:00,5:00, and 8:00 P.M.) for twenty consecutive days. The data are presented in the table, along with a SAS printout with summary statistics

a. Construct an i-chart from the given data.

b. What does the chart suggest about the stability of the filling process (whether the process is in or out of statistical control)? Justify your answer.

c. Should the control limits be used to monitor future process output? Explain

d. Two shifts of workers run the filling operation. Each day the second shift takes over at 3:00 P.M. Will the rational subgrouping strategy used by K-Company facilitate or hinder the identification of process variation caused by differences in the two shifts? Explain.