QUESTION $9$

Refer to the attached Excel file $"$HW Control Charts" using the $"$R$-$Chart" tab data; the X$-$DbIBar and R$-$Bar of those samples are:

X$-$DblBar:$8\mathrm{.}08,$ R$-$Bar:$0\mathrm{.}05$

X$-$DbBar:$9\mathrm{.}08,$ R$-$Bar:$0\mathrm{.}06$

X$-$DbBar:$9\mathrm{.}80,$ R$-$Bar:$0\mathrm{.}05$

X$-$DblBar:$9\mathrm{.}08,$ R$-$Bar:$0\mathrm{.}50$

X$-$DblBar:$9\mathrm{.}08,$ R$-$Bar:$0\mathrm{.}05$