Ten samples were collected from a production line. Each sample contains 7 units (observations). You are asked to develop an X chart to monitor the average of the 7 units based on the ten samples. Assume the averages of the 10 samples are X11 , X22 , ...., X1010 . Each of the ten x-bar values is obtained from averaging the measures of the 7 randomly collected units in a sample. The sum X11 + X22 + ....+ X1010 =800. The sum of the ranges from the ten samples, R₁+R2+...+R₁₀=56. [Since partial results are given, no detailed sample measures on the individual units are needed.]

Construct a 3 mean chart (X-bar chart) using Table 10.3 (Round all answers to three decimal places.)

(1) The quality standard is (the center line):

(2) The lower control limit is (LCL):

Construct a 3 R chart:

(3) The quality standard is (the center line):

(4) The upper control limit is (UCL):