I was struggling with the same question when I came across this topic. I though it’s best to share my findings.
1. Z (ucl) = 1 > Area to the left of UCL = 0.8413 (from table)
2. Since we want the area to the right of UCL (upper rejection zone) : 1 – 0.8413 = 0.1586 — A
3. Z (lcl) = -0.6818 > Area to the left of LCL = 0.2483…[Read more]