plotting

[siewking]

I would like to see the relationship between POP (independent variable) and BOC (dependent variable). Therefore, I square the POP and there is an inverted relationship between POP and BOC, holding other factors constant. I have plotted the relationship between BOC and POP using scatter plot based on the raw data of POP and BOC. But, I also would like to plot the estimated BOC and POP. How can I get the estimated value of BOC so that I can plot estimated BOC against the raw data of POP? i attached my work here. Thank you. :