A quality analyst is checking the process capability associated with the production of struts, specifically the amount of torque used to tighten a fastener. Twenty$-$five samples of size $4$ have been taken. These were used to create

X

$$

and R charts. The values for these charts are as follows. The upper and lower control limits for the

X

$$

chart are $74\mathrm{.}80$ Nm and $72\mathrm{.}37$ Nm$,$ respectively.

X

$$

$$

is $73\mathrm{.}58$ Nm$.$

R

$$

is $1\mathrm{.}66.$ The specification limits are

$80$

$$Nm

$\backslash$pm

$10.$

Calculate

$6$

$$

$^$

$,$

$$C

p

$,$

and

C

pk

$.$

Interpret the values.