$6\mathrm{.}34.$ Specifications on a cigar lighter detent are $0\mathrm{.}3220$

and $0\mathrm{.}3200$ in$.$ Samples of size $5$ are taken every $45$

min with the results shown in Table $6$E$.17($measured

as deviations from $0\mathrm{.}3210$ in $0\mathrm{.}0001in..$

$($a$)$ Set up an $R$ chart and examine the process for

statistical control.

$($b$)$ What parameters would you recommend for an

$R$ chart for on$-$line control?

$($c$)$ Estimate the standard deviation of the process.

$($d$)$ What is the process capability?

$6\mathrm{.}35.$ Continuation of Exercise $6\mathrm{.}34.$ Reconsider the data

from Exercise $6\mathrm{.}34$ and establish $\stackrel{}{x}$ and $R$ charts with

appropriate trial control limits$.$ Revise these trial lim$-$

its as necessary to produce a set of control charts for

monitoring future production. Suppose that the

$($a$)$ Plot these new observations on the control chart. What conclusions can you draw about process stability?

$($b$)$ Use all $25$ observations to revise the control lim$-$ its for the x and R charts. What conclusions can you draw now about the process? $$ TABLE $6E\mathrm{.}17$

Data for Exercise $6\mathrm{.}34.$

TABLE $6$E$.18$

New Data for Exercise $6\mathrm{.}35$