Question $32$

$2pts$

The mean service time $(\stackrel{}{x})$ of a hairdresser is $18$ minutes with a standard deviation $()$ of $2$ minutes. Upper specification limit $($USL$)$ is $22$ minutes, whereas lower specification limit $(LSL)$ is $15$ minutes for this process. What is the process capability index $(c_{pk})$ for this process? Is the process capable?

Cpk$=0\mathrm{.}5,$ not capable

Cpk$=0\mathrm{.}67,$ capable

Cpk$=1\mathrm{.}5,$ capable

Cpk$=0\mathrm{.}5,$ capable

Cpk$=0\mathrm{.}67,$ not capable