The following data is obtained from a process control chart

$\backslash$table$[[$Sample #$,$# defects$],[1,23],[2,34],[3,15],[4,30],[5,25],[6,22],[7,18]]$

If the number of observations for each sample is $150$ units, what is the $3-$sigma upper control limit of the process?

$0\mathrm{.}2486$

$0\mathrm{.}0694$