Required information

The quality$-$control plan for a certain production process involves taking samples of size $4.$ The results from the last $31\mathrm{.}00$

samples can be summarized as follows:

${\displaystyle \underset{i=1}{\overset{31\mathrm{.}00}{}}}{\stackrel{}{x}}_i=712\mathrm{.}5,{\displaystyle \underset{i=1}{\overset{31\mathrm{.}00}{}}}{R}_i=143\mathrm{.}7,{\displaystyle \underset{i=1}{\overset{31\mathrm{.}00}{}}}{s}_i=62\mathrm{.}5$

Using the sample ranges, compute the $3$ control limits for the $\stackrel{}{x}$ chart.

$($Round the final answer to three decimal places.$)$

The LCL is

The UCL is