The plot request plots Expenditures on the vertical axis, plots DropoutRate on the horizontal axis, and specifies an asterisk as the plotting symbol. HREF= draws a reference line extending from 28.6 on the horizontal axis. The reference line represents the national average. 
    plot expenditures*dropoutrate='*' / href=28.6;
    title 'Plot of Dropout Rate and Expenditure Per Pupil';
 run;