Eight samples $($m$=8)$ of size $4($n$=4)$ have been collected from a manufacturing process that

is in statistical control, and the dimension of interest has been measured for each part.

Determine the values of the centre, LCL and UCL for x $$and R charts, and draw both charts.

The calculated x $$and R values in cm are listed below. Take values for D$3$ and D$4$ based on

a sample size n $=4$ to be D$3=0,$ D$4=2\mathrm{.}282$