Question $8$

For an R$-$chart, what is the UCL $($use the chart of control chart constants$)$ rounded to two places after the decimal when the average range is $5\mathrm{.}2$ based on $15$ samples of size $10$

$1$ point

$8\mathrm{.}58$

$9\mathrm{.}26$

$10\mathrm{.}91$

$7\mathrm{.}79$