a$.$ Set up $$and $$ charts on this process. Does the process seem to be in statistical control? If

necessary, revise the trial control limits$.(25$ marks$)$

Hint: If some non$-$conforming points $($crossing the UCL or LCL$)$ found either in $$or $$ chart,

those out$-$of$-$control points must be excluded from the control limit calculations and the calculation

should be redone for both $$or $$ chart regardless of which one contains the nonconforming data.

b$.$ If specifications on the diameter are $0\mathrm{.}5030\backslash$pm $0\mathrm{.}0010,$ find the percentage of nonconforming

bearings produced by this process. Assume that diameter is normally distributed. $(10$ marks$)$