J$.$ McWilliams Swim Club is trying to calibrate their chlorine pump to ensure that the right amount of chlorine $(1\mathrm{.}01\mathrm{.}5$ ppm of free chlorine$)$ is mixed into the water. Thirty samples of four readings at random times during the week were taken. These data can be found in the sheet $1$ of Excel file ICE $5.$xlsx$.$

a$.$ Compute the mean and range of each sample, calculate control limits$,$ and plot them on X$-$bar and R control charts.

b$.$ Does the process appear to be in statistical control?

A$2=0\mathrm{.}729$; D$3=0$; D$4=2\mathrm{.}282$