hi all,
i got a standard dispersion correct chart, but i can't draw the same chart when i deal with actual data.

[link Point to another website Only the registered members can access] Figure 1. standard chart

[link Point to another website Only the registered members can access] Figure 2. i dealed..

so, my question is:
1. in the figure 1, the dispersion correct curve pointed by the number 1, how to draw the yellow part? And what's that mean??
2. How to draw the black thick line poined by the number 2 ?And what's that mean???

Regards and thanks everyone.