Hi,
I just want to ask if my answers are correct in getting trial central line and control limits. Subgroup size is 4. Subgroup number is 25.
The given are:
∑ (X-bar) = 12063
∑R= 626
X-double bar= 482.52
R-bar= 25.04
A_{2 = 0.729 }
D_{4} = 2.282
D_{3} = 0
UCLx̄= (X-double bar)+A
2 (R-Bar)
= 482.52+ 0.729(25.04)
= 500.77
LCLx̄= (X-double bar)-A
2 (R-Bar)
= 482.52- 0.729(25.04)
= 464.27
_{
UCL (R-bar)= D4(R-bar) }
= 2.282(25.04)
= 57.14
LCL (R-bar)= D_{3}(R-bar)
= 0(25.96)
=0
Did I use the correct formulas?
Thanks I hope you can helpme.