Suppose That 25 Samples, Each of Size 100, Were Selected $\sum \hat { p } _ { i} = 1.8$

Short Answer

Suppose that 25 samples, each of size 100, were selected from what is believed to be an in-control process, and that $\sum \hat { p } _ { i} = 1.8$ where $\hat { p } _ { i }$ is the fraction of defective items in sample i. The p chart for the fraction of defective items has its center line at height equals to __________.