UCL (Upper control limit) Mean Range 12.6856 1.0193 CL (Center line) 12.36 0.67 LCL (Lower control limit) 12.0344 0 Sample Number Item1 Item2 Item3 Item4 Mean Range Sample 1 12.2 12.6 12 12.1 12.225 0.6 Sample 2 11.9 12.5 12.4 12.7 12.375 0.8 Sample 3 12 12.2 12.9 13.1 12.55 1.1 Sample 4 12.5 12.5 12.4 12.8 12.55 0.4 Sample 5 12.2 12.8 12.7 12 12.425 0.8 Sample 6 12.1 12.5 11.8 12.3 12.175 0.7 Sample 7 12.3 12.4 12.8 12.4 12.475 0.5 Sample 8 12 12.1 12.4 12.2 12.175 0.4 Sample 9 12.1 12.8 12.4 11.9 12.3 0.9 Sample 10 12.6 12.4 12.1 12.3 12.35 0.5 What is the mean of sample 8. Write your answer according to 3 decimal places.