Process time at a workstation is monitored charts. Six samples of n = 12 observations have been obtained ar (in minutes): Sample Mean Range 3.12 3.21 0.50 0.41 0.44 0.54 3.12 3.05 3.05 0.52 3.13 0.55 Process time at a workstation is monitored charts. Six samples of n = 12 observations have been obtained ar (in minutes): Sample Mean Range 3.12 3.21 0.50 0.41 0.44 0.54 3.12 3.05 3.05 0.52 3.13 0.55