Fifteen Random Samples of Size Four Yield the Following Statistics:Sample $\bar { X }$

Fifteen random samples of size four yield the following statistics:Sample $\bar { X }$ R Sample $\bar { X }$ R Sample $\bar { X }$ R
$\begin{array} { c c c c c c c c c } 1 & 331 & 8 & 6 & 333 & 4 & 11 & 332 & 6 \\2 & 333 & 5 & 7 & 332 & 13 & 12 & 335 & 7 \\3 & 335 & 8 & 8 & 331 & 5 & 13 & 330 & 7 \\4 & 337 & 7 & 9 & 334 & 6 & 14 & 330 & 5 \\5 & 336 & 9 & 10 & 332 & 9 & 15 & 334 & 6\end{array}$
For these data, determine the upper and lower control limits for the $\bar { X }$ and R charts.