A company produces a liquid which can vary in its pH levels unless the production process is carefully controlled. Quality control technicians routinely monitor the pH of the liquid. The quality control plan calls for collecting samples of size three from batches produced each hour for one day. The complete list of samples and their measured values are as follows: (14 marks) Sample pH level Sample Mean Sample Range 6.2 5.9 6.5 5.4 5.6 6.4 5.2 5.5 5.7 4.8 6.4 6.3 5.3 6.8 6.3 7.3 7.3 6.8 6.8 6.6 5.4 6.6 6.7 6.4 6.4 6.1 6.2 6.3 6.5 6.7 6.6 6.4 18 6.9 6.8 6.8 6.9 19 62 7.1 7.1 6.2 20 5.5 6.7 6.6 5.4 21 6.6 5.2 5.4 6.5 22 6.4 6.2 6.3 23 6.4 4.6 4.8 6.3 24 7.0 6.3 6.4 7.2 a) Complete the table with sample mean and sample range. b) By using Microsoft excel, calculate the lower control limit (LCL) and upper control limit (UCL) and construct an X' chart. Based on the control chart you, decide whether or not the t process is in control. If not, state which of the decision rules applies. e) By using Microsoft excel, calculate the lower control limit (LCL) and upper control limit (UCL) and construct an R chart. Based on the control chart, decide whether or not the process is in control. If not, state which of the decision rules applies. 34°C Mostly sunny 12245 3 6 7 8 9 10 11 12 13 14 TUTTE 15 16 17 sonrie 000076 5.8 6.4 5.8 5.7 65 5.2 335655 5.1 5.8 4.9 6.4 2189SHEK6666 79NO 354 6666 6.9 72 6.9 5.3 65 93 2922 NINC 6.5 665 6.9 5.2 6.4 5556565 5.7 5.2 52 ONMNN00 6.0 5.7 6.3 5.2 6.2 7.4 6564 206 6.0 6.0 5.3 5.5 5.0 6.7 5.8 5.6 6.2 5.6 4.4 6.2 6.7 6.1 6.2 49 7.0 5.4 6.7 4.7 6.7 6.8 5.9 6.7 79562 69 68664 vile 66 62 6.1 6.8 5.3 6.5 5.8 5.4 5.3 lenn 22003W Talas 6.2 5.8 +2400