Anormally distributed quality characteristic is monitored throughuse of an x bar and r chart. these charts have the followingparameters n=4x barchart r chartucl=626 ucl=18.795center line=620 center line =8.236lcl=614 lcl=0
both charts exhibit control. a) what is the estimated standard deviation of the process? b) suppose an s chart were to be substituted for the r chart. whatwould be the appropriate parameters of the s chart? c) if specifications on theproduct were 610 +/- 15, what would be your estimate of the processfraction nonconforming? d) what could be done to reduce this fraction nonconforming? e) what is the probability of detecting a shift in the process mean to610 on the first sample following the shift (sigma remainsconstant)? f) what is the probability ofdetecting a shift in part (e) by at least the third sample afterthe shift occurs?