a$)$ Find X$-$bar chart control limits$.$

b$)$ Find R$-$chart control limits$.$

c$)$ Is the process in control? Why?

d$)$ The part specifications require a weight of $4\mathrm{.}0$ pounds with a tolerance of $+-0\mathrm{.}1$ pounds. Is the process capable $/$ six$-$sigma capable of producing the part according to specification $($you can assume that the process is centered$)?$ Why?