A factory is producing a copper plate with a thickness randomly distributed with mean 10mm and standard deviation 2mm. For statistical process control, 4 products are selected as random sample and average thickness is calculated daily as follows: Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 9 Day 10 Day 11 Day 12 Day 13 Day 14 Day 15 Day 16 Sample Mean (mm) 9.4 11.5 10.7 8.3 7.9 9.6 8.8 7.3 6.9 8.3 7.2 7.1 7.9 8.9 9.1 9.9 Evaluate the sample mean based on 4 Western Electric Rules as follows: Rule 1: If the measurement deviates more than 3 standard deviation from theoretical mean, there is something wrong in the process Rule 2: If 2 out of 3 consecutive measurements deviates more than 2 standard deviations from theoretical mean, there is something wrong in the process Rule 3: If 4 out of 5 consecutive measurements deviates more than 1 standard deviations from theoretical mean, there is something wrong in the process Rule 4: If 9 consecutive measurements are either above or below theoretical mean, there is something wrong in the process