A manager wishes to build a control chart for a process. A total of five (05) samples are collected with five (05) observations within each sample. The sample means (X-bar) are: 15.36, 14.61,16.36,20.28, and 15.77 respectively. Also, the corresponding ranges are; 10.79, 8.37.2.81,8.17, and 3.31 respectively. The lower and upper control limits of the x-bar chart are respectively of stion Select one: O a. None is correct b. 12.40, 19.72 O 18.55, 13.47 d. 12.60, 20.36 O e. 16.55, 11:47