Question $2[15$ marks$]$

Determine the trial central line and control limits for a $p$ chart using the following data, which are for the

payment of dental insurance claims.

a$)$ Plot the values on graph paper and determine if the process is stable. $[5$ marks$]$

b$)$ If there are any out$-$of$-$control points, assume an assignable cause and determine the revised

central line and control limits$.[10$ marks$]$