The specification for a plastic liner for concrete highway projects calls for a thickness of $6\mathrm{.}0$ mm $0\mathrm{.}1$ mm$.$ The standard deviation of the process is estimated to be $0\mathrm{.}02$ mm$.$The process is known to operate at a mean thickness of $6\mathrm{.}03$ mm$.$ What is Cok for this process? give answer in $2$ dp$.$