30 samples of size 6 each were taken from a lathe machine that employs a "turning" process to produce the outer diameter of engine cylinders. The diameter specifications by designer are given to as 20.00 + 0.10 mm.The process average of the outer diameters turned out to be 19.920 mm.The average range of the same samples turned out to be 0.255.Develop the upper and lower control limits for the chart(s) that you think is (are) most appropriate for this situation.

a.----- chart name ( P chart or C chart or variable chart

i.Average =

ii.UCL formula:____________________

iii.Plug in numbers (show work y typing)________________________

iv.LCL formula:______________

v.Plug in numbers (show work) ___________________