In a fabric manufacturing factory, the quality control process using control charts from SPC. In an hour there are a total of 5 samples are taken each having 5 observations regarding the thickness of fabric in measured in millimeters. In a particular hour, the sample means (X-bar) are noted to be: 156.46, 199.62, 189.31, 102.22, and 112.09 respectively. In the same sample, the corresponding ranges are: 11.97, 12.17, 13.94, 11.86, and 11.83 respectively. What are the lower and upper control limits for the X-bar chart? a. 156.55.170.47 O b. None is correct c. 143.55,165.47 d. 142.92, 160.66 e. 145.40, 190.72 f. 144.77.159.11