The table below indicates the average tensile strengths of metal pipes sampled in groups of $5$ observations each. What is the value of UCL for the $x-$bar chart?

Table $3.$

$\backslash$table$[[,$Average,Range$],[$Batch A$,3\mathrm{.}1,0\mathrm{.}4],[$Batch B$,2\mathrm{.}5,0\mathrm{.}6],[$Batch C$,1\mathrm{.}6,0\mathrm{.}7],[$Batch D$,3\mathrm{.}4,0\mathrm{.}2],[$Batch E$,1\mathrm{.}8,0\mathrm{.}3],[$Batch F$,1\mathrm{.}7,0\mathrm{.}5]]$

$2\mathrm{.}6$

$2\mathrm{.}8$

$3\mathrm{.}0$

$3\mathrm{.}6$