A part that connects two metal components should have a distance of 4 inches between two drilled holes. It has been determined that x-bar and R-charts should be set up to determine if the drilling process is in statistical control. Ten samples of size four were collected and the associated sample means and range values calculated.

C. To the nearest thousandth, the 3-sigma (see e-text Page 251) lower control limit for the sample means is .

D. To the nearest thousandth, the 3-sigma upper control limit for the sample means is .

E. To the nearest thousandth, the 3-sigma lower control limit for the sample ranges is .

F. To the nearest thousandth, the 3-sigma upper control limit for the sample ranges is .

G. Is this process in control? Enter YES or NO.

Mean Range (inches) (inches) Sample 1 4.01 0.04 Sample 2 3.98 0.06 Sample 3 4.00 0.02 Sample 4 3.99 0.05 Sample 5 4.02 0.06 Sample 6 3.97 0.02 Sample 7 4.02 0.02 Sample 8 3.99 0.04 Sample 9 3.98 0.05 Sample 10 4.01 0.06