Use the data in the attached Excel file to construct a (i) mean (X-bar) control chart and (ii) range (R) control chart. The file contains values for the length of wooden boards cut in a production process. Values are provided for eight samples (each with six observations). Make sure and briefly mention whether the process appears in control or out of control (sample mean above the UCL or below the LCL).

Sample. 1 2 3 4 5 6 7 8

Observation

1

72.10 73.00 72.00 74.00 72.10 75.00 72.30 72.00

2

71.50 72.10 71.40 72.00 71.50 76.50 71.80 71.50

3

72.00 72.30 71.80 72.10 72.40 72.30 72.40 73.10

4

72.30 71.80 71.30 71.20 72.30 73.40 71.20 71.40

5

73.40 71.30 72.10 71.50 73.00 75.40 70.80 72.30

6

74.20 71.90 72.20 71.30 71.80 72.10 71.30 71.40