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: 172.11, 219.58, 208.24, 112.44, and 123.30 respectively. In the same sample, the corresponding ranges are: 13.17, 13.38, 15.34, 13.04, and 13.02 respectively What are the lower and upper control limits for the R chart? Oa. 0,28.67 O b. 0,31.47 O c. None is correct O d. 0.29.67 e. 0,29.17 Of. 0.30.98