Process time at a workstation is monitored using sample mean and range control charts. Six samples of n = 15 observations have been obtained and the sample means and ranges computed (in minutes) as follows: Sample 1 2 Mean 3.30 3.16 3.21 3.30 3.27 13.20 Range .49 .41 1.47 .49 46 3 4 15 6 .54 What are the upper and lower limits for sample mean control chart? (Round the intermediate calculations to 2 decimal places. Round the final answers to 2 decimal places.) O LCL = 3.22, UCL = 3.53 LCL = 3.13, UCL = 3.35 LCL = 3.32, UCL = 3.64 OLCL = 3.04, UCL = 3.42 It cannot be calculated