Control limits for np Chart if a standard value of p is available: LCL = n - 3, n(1–- P). CL =np, UCL= nɔ + 3/np(1- 5) LCL = np – 3 np(1-p), CL = np, UCL = np+3,fnp(1-p) a) b) P(1- p) P(1-p) c) LCL = p - 3, CL = p, UCL = p +3, P(1-F) P(1-F) d) LCL = p – 3, CL = p, UCL = p +3,

In a 2-proportion test, two separate proportions are measured at the same time, and their similarity is evaluated. It is also known as a 2-proportion z-test, and a comparison of two different proportions is done in this method.