Five data entry operators work at the data processing department of the Birmingham Bank. Each day for $30$ days, the number of defective records in a sample of $250$ records typed by these operators has been noted, as follows:

$\backslash$table$[[\backslash$table$[[$Sample$],[$No$.]],\backslash$table$[[$No$.],[$Defectives$]],\backslash$table$[[$Sample$],[$No$.]],\backslash$table$[[$No$.],[$Defectives$]],\backslash$table$[[$Sample$],[$No$.]],\backslash$table$[[$No$.],[$Defectives$]]],[1,7,11,7,21,18],[2,5,12,6,22,13],[3,20,13,15,23,6],[4,9,14,3,24,8],[5,12,15,12,25,12],[6,7,16,7,26,9],[7,13,17,12,27,15],[8,9,18,4,28,5],[9,6,19,18,29,12],[10,13,20,17,30,4]]$

a$)$ Establish $3$ upper and lower control limits$.$

$UC{L}_p=($enter your response as a number between $0$ and $1,$ rounded to three decimal places$).$