Process time at a workstation is monitored using sample mean and range control charts. Six samples with 10 observations each have been obtained and the sample means and ranges computed (in minutes) as follows: 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.) LCL=4.01,UCL=4.47LCL=4.13,UCL=4.35LCL=4.28,UCL=4.68LCL=4.17,UCL=4.79 It cannot be calculated