Mr. K. R. Wood, president of Broccoli Enterprises, is interested in the data shown in Table 18.5.4, representing the lengths of broccoli trees after cutting.
a. Find the average, X, and the range, R, for each sample.
b. Find the overall average, X, and the average range, R.
c. Find the center line for the X chart.
d. Find the control limits for the X chart.
e. Draw the X chart.
f. Comment on what you see in the X chart. In particular, is this process in control? How do you know?
g. Write a paragraph summarizing the situation and defending the action you feel is appropriate.